The molecular landscape of osteogenesis imperfecta in a Brazilian tertiary service cohort

We have sought the molecular diagnosis of OI in 38 Brazilian cases through targeted sequencing of 15 candidate genes. While 71% had type 1 collagen-related OI, defects in FKBP10, PLOD2 and SERPINF1, and a potential digenic P3H1/WNT1 interaction were prominent causes of OI in this underrepresented population.

INTRODUCTION

Defects in type 1 collagen reportedly account for 85-90% of osteogenesis imperfecta (OI) cases, but most available molecular data has derived from Sanger sequencing-based approaches in developed countries. Massively parallel sequencing (MPS) allows for systematic and comprehensive analysis of OI genes simultaneously. Our objective was to obtain the molecular diagnosis of OI in a single Brazilian tertiary center cohort.

METHODS

Forty-nine individuals (84% adults) with a clinical diagnosis of OI, corresponding to 30 sporadic and 8 familial cases, were studied. Sixty-three percent had moderate to severe OI, and consanguinity was common (26%). Coding regions and 25-bp boundaries of 15 OI genes (COL1A1, COL1A2, IFITM5 [plus 5'UTR], SERPINF1, CRTAP, P3H1, PPIB, SERPINH1, FKBP10, PLOD2, BMP1, SP7, TMEM38B, WNT1, CREB3L1) were analyzed by targeted MPS and variants of interest were confirmed by Sanger sequencing or SNP array.

RESULTS

A molecular diagnosis was obtained in 97% of cases. COL1A1/COL1A2 variants were identified in 71%, whereas 26% had variants in other genes, predominantly FKBP10, PLOD2, and SERPINF1. A potential digenic interaction involving P3H1 and WNT1 was identified in one case. Phenotypic variability with collagen defects could not be explained by evident modifying variants. Four consanguineous cases were associated to heterozygous COL1A1/COL1A2 variants, and two nonconsanguineous cases had compound PLOD2 heterozygosity.

CONCLUSIONS

Novel disease-causing variants were identified in 29%, and a higher proportion of non-collagen defects was seen. Obtaining a precise diagnosis of OI in underrepresented populations allows expanding our understanding of its molecular landscape, potentially leading to improved personalized care in the future.

Spontaneous fertility in a male patient with testotoxicosis despite suppression of FSH levels

Testotoxicosis is a rare cause of peripheral precocious puberty in boys caused by constitutively activating mutations of the LHCG receptor. Affected males usually have normal gonadotropin profiles and fertility in their adult life. Here, we described the long-term follow-up of a 24-year-old young man with severe testotoxicosis due to a de novo activating mutation in the third transmembrane helix of the LHCGR (p.Leu457Arg). This patient was treated with different medications, including medroxyprogesterone acetate, ketoconazole, cyproterone acetate and aromatase inhibitor from age 2.5 to 9.5 years. His basal and GnRH-stimulated gonadotropin levels were continually suppressed during and after medical treatment. At adulthood, extremely high serum testosterone levels (>35 nmol/L), undetectable gonadotropin levels (LH < 0.15 IU/L and FSH < 0.6 IU/L) and oligozoospermia were evidenced. Despite his suppressed FSH levels and an unfavorable spermogram, the patient fathered a healthy girl and biological paternity was confirmed through analysis of microsatellites. Spontaneous fertility in a young man with severe testotoxicosis and chronic suppression of FSH levels reinforces the key role of high intratesticular testosterone levels in human spermatogenesis.

Malignant testicular germ cell tumors in postpubertal individuals with androgen insensitivity: prevalence, pathology and relevance of single nucleotide polymorphism-based susceptibility profiling

STUDY QUESTION

What is the prevalence of malignant testicular germ cell tumors (TGCT) and its precursors, (pre-) germ cell neoplasia in situ (GCNIS), in late teenagers and adults who have androgen insensitivity syndrome (AIS) and the impact of an individual's genetic susceptibility to development of TGCT?

SUMMARY ANSWER

No GCNIS or TGCT was diagnosed, but pre-GCNIS was identified in 14 and 10% of complete and partial AIS patients, respectively, and was associated with a higher genetic susceptibility score (GSS), with special attention for KITLG (rs995030) and ATFZIP (rs2900333).

WHAT IS KNOWN ALREADY

Many adult women with AIS decline prophylactic gonadectomy, while data regarding the incidence, pathophysiology and outcomes of TGCT in postpubertal individuals with AIS are lacking. The relevance of genetic factors, such as single nucleotide polymorphisms (SNPs), in predisposing AIS individuals to TGCT is unknown.

STUDY DESIGN, SIZE, DURATION

This multicenter collaborative study on prophylactically removed gonadal tissue was conducted in a pathology lab specialized in germ cell tumor biology.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Material from 52 postpubertal individuals with molecularly confirmed AIS (97 gonadal samples) was included; the median age at surgery was 17.5 (14-54) years. Immunohistochemical studies and high-throughput profiling of 14 TGCT-associated SNPs were performed. The main outcome measures were the prevalence of pre-GCNIS, GCNIS and TGCT, and its correlation with a GSS, developed based on the results of recent genome-wide association studies.

MAIN RESULTS AND ROLE OF CHANCE

The earliest recognizable change preceding GCNIS, referred to as pre-GCNIS, was present in 14% of individuals with complete and 10% of those with partial AIS at a median age of 16 years. No GCNIS or invasive TGCT were found. The median GSS was significantly greater for those with, compared to those without, pre-GCNIS (P = 0.01), with an overlap between groups. Our data suggest important roles for risk alleles G at KITLG (rs995030) and C at ATFZIP (rs2900333), among the 14 studied TGCT-associated SNPs.

LARGE SCALE DATA

N/A.

LIMITATIONS REASONS FOR CAUTION

A limited number of cases were included.

WIDER IMPLICATIONS OF THE FINDINGS

Our data suggest that the prevalence of pre-GCNIS in individuals with AIS beyond puberty is around 15%. Genetic susceptibility likely contributes to pre-GCNIS development in AIS but factors related to malignant progression remain unclear. Although data in older patients remain scarce, malignant progression appears to be a rare event, although the natural history of the premalignant lesion remains unknown. Therefore, the practice of routine prophylactic gonadectomy in adults with AIS appears questionable and the patient's preference, after having been fully informed, should be decisive in this matter.

STUDY FUNDING/COMPETING INTEREST(S)

This study was supported by research grants from the Research Foundation Flanders (FWO) (to M.C.), the Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq G0D6713N) (to B.B.M. and M.C.) and the European Society for Pediatric Endocrinology (ESPE), granted by Novo Nordisk AB (to J.K.). There are no competing interests.

Identification of the first homozygous 1-bp deletion in GDF9 gene leading to primary ovarian insufficiency by using targeted massively parallel sequencing

Targeted massively parallel sequencing (TMPS) has been used in genetic diagnosis for Mendelian disorders. In the past few years, the TMPS has identified new and already described genes associated with primary ovarian insufficiency (POI) phenotype. Here, we performed a targeted gene sequencing to find a genetic diagnosis in idiopathic cases of Brazilian POI cohort. A custom SureSelect^XT DNA target enrichment panel was designed and the sequencing was performed on Illumina NextSeq sequencer. We identified 1 homozygous 1-bp deletion variant (c.783delC) in the GDF9 gene in 1 patient with POI. The variant was confirmed and segregated using Sanger sequencing. The c.783delC GDF9 variant changed an amino acid creating a premature termination codon (p.Ser262Hisfs*2). This variant was not present in all public databases (ExAC/gnomAD, NHLBI/EVS and 1000Genomes). Moreover, it was absent in 400 alleles from fertile Brazilian women screened by Sanger sequencing. The patient's mother and her unaffected sister carried the c.783delC variant in a heterozygous state, as expected for an autosomal recessive inheritance. Here, the TMPS identified the first homozygous 1-bp deletion variant in GDF9. This finding reveals a novel inheritance pattern of pathogenic variant in GDF9 associated with POI, thus improving the genetic diagnosis of this disorder.

Discriminating between virilizing ovary tumors and ovary hyperthecosis in postmenopausal women: clinical data, hormonal profiles and image studies

BACKGROUND

The presence of virilizing signs associated with high serum androgen levels in postmenopausal women is rare. Virilizing ovarian tumors (VOTs) and ovarian stromal hyperthecosis (OH) are the most common etiologies in virilized postmenopausal women. The differential diagnosis between these two conditions is often difficult.

OBJECTIVE

To evaluate the contribution of clinical features, hormonal profiles and radiological studies to the differential diagnosis of VOT and OH.

DESIGN

A retrospective study.

SETTING

A tertiary center.

MAIN OUTCOME MEASURES

Clinical data, hormonal status (T, E2, LH and FSH), pelvic images (transvaginal sonography and MRI) and anatomopathology were reviewed.

PATIENTS

Thirty-four postmenopausal women with a diagnosis of VOT (13 women) and OH (21 women) were evaluated retrospectively.

RESULTS

Clinical signs of hyperandrogenism were more prevalent in the VOT group than the OH group. Although the VOT group showed higher T and E2 levels and lower gonadotropin levels than the OH group, a great overlap occurred among the hormone levels. A pelvic MRI provided an accurate differentiation of these two conditions.

CONCLUSION

In this group of patients, the main features contributing to the differential diagnosis of VOT and OH were serum levels of testosterone and gonadotropins and the presence of an ovarian nodule identified on the MRI. Although the association of clinical, hormonal and radiological features contributes to the differential diagnosis of these two conditions, histopathological analysis remains the gold standard for the diagnosis of ovarian hyperandrogenism in postmenopausal women.

Effects of Type 1 Insulin-Like Growth Factor Receptor Silencing in a Human Adrenocortical Cell Line

Type 1 insulin-like growth factor receptor (IGF-1R) is overexpressed in a variety of human cancers, including adrenocortical tumors. The aim of the work was to investigate the effects of IGF-1R downregulation in a human adrenocortical cell line by small interfering RNA (siRNA). The human adrenocortical tumor cell line NCI H295R was transfected with 2 specific IGF1R siRNAs (# 1 and # 2) and compared with untreated cells and a negative control siRNA. IGF1R expression was determined by quantitative reverse-transcription PCR (qRTPCR) and Western blot. The effects of IGF-1R downregulation on cell proliferation and apoptosis were assessed. IGF-1R levels were significantly decreased in cells treated with IGF-1R siRNA # 1 or # 2. Relative expression of IGF1R mRNA decreased approximately 50% and Western blot analysis revealed a 30% of reduction in IGF-1R protein. Downregulation of this gene resulted in 40% reduction in cell growth in vitro and 45% increase in apoptosis using siRNA # 2. These findings demonstrate that decreasing IGF-1R mRNA and protein expression in NCI H295R cells can partially inhibit adrenal tumor cell growth in vitro. Targeting IGF1R is a promising therapy for pediatric malignant adrenocortical tumor and can still be an option for adult adrenocortical cancer based on personalized genomic tumor profiling.

DAX1 Overexpression in Pediatric Adrenocortical Tumors: A Synergic Role with SF1 in Tumorigenesis

DAX1 transcription factor is a key determinant of adrenogonadal development, acting as a repressor of SF1 targets in steroidogenesis. It was recently demonstrated that DAX1 regulates pluripotency and differentiation in murine embryonic stem cells. In this study, we investigated DAX1 expression in adrenocortical tumors (ACTs) and correlated it with SF1 expression and clinical parameters. DAX1 and SF1 protein expression were assessed in 104 ACTs from 34 children (25 clinically benign and 9 malignant) and 70 adults (40 adenomas and 30 carcinomas). DAX1 gene expression was studied in 49 ACTs by quantitative real-time PCR. A strong DAX1 protein expression was demonstrated in 74% (25 out of 34) and 24% (17 out of 70) of pediatric and adult ACTs, respectively (χ(2)=10.1, p=0.002). In the pediatric group, ACTs with a strong DAX1 expression were diagnosed at earlier ages than ACTs with weak expression [median 1.2 (range, 0.5-4.5) vs. 2.2 (0.9-9.4), p=0.038]. DAX1 expression was not associated with functional status in ACTs. Interestingly, a positive correlation was observed between DAX1 and SF1 protein expression in both pediatric and adult ACTs (r=0.55 for each group separately; p<0.0001). In addition, DAX1 gene expression was significantly correlated with SF1 gene expression (p<0.0001, r=0.54). In conclusion, DAX1 strong protein expression was more frequent in pediatric than in adult ACTs. Additionally, DAX1 and SF1 expression positively correlated in ACTs, suggesting that these transcription factors might cooperate in adrenocortical tumorigenesis.

CYP21A2 genotypes do not predict the severity of hyperandrogenic manifestations in the nonclassical form of congenital adrenal hyperplasia

There is a strong correlation between the severity of genotypes and 17OH-progesterone levels in patients with the nonclassical form of 21-hydroxylase deficiency (NC-CAH); however, there are few studies regarding the correlation with clinical signs. The aim of the study was to evaluate whether genotypes correlate with the severity of the hyperandrogenic phenotype. A cohort of 114 NC-CAH patients were diagnosed by stimulated-17OHP ≥10 ng/ml. CYP21A2 genotypes were divided into 2 groups according to the severity of enzymatic impairment; mild and severe. Clinical data and hormonal profiles were compared between the 2 groups. Age at onset of manifestations did not differ between children or adults carrying both mild and severe genotypes. Frequencies of precocious pubarche and hirsutism, with or without menstrual abnormalities, were similar between the 2 groups. There were no differences in basal testosterone levels of adult symptomatic females carrying both genotypes, but there were differences between adult females with (92.9±49.5 ng/dl) and without hirsutism (43.8±38 ng/dl) (p=0.0002). Similar frequencies of both genotypes were observed in asymptomatic females and in those with clitoromegaly. Nonclassical genotypes do not predict the severity of phenotype. Asymptomatic and virilized females carrying the same genotype suggest that there is a modulatory effect of genes involved in the androgen pathway on the phenotype.

Mutations of the KISS1 gene in disorders of puberty

CONTEXT

Kisspeptin, encoded by the KISS1 gene, is a key stimulatory factor of GnRH secretion and puberty onset. Inactivating mutations of its receptor (KISS1R) cause isolated hypogonadotropic hypogonadism (IHH). A unique KISS1R-activating mutation was described in central precocious puberty (CPP).

OBJECTIVE

Our objective was to investigate KISS1 mutations in patients with idiopathic CPP and normosmic IHH.

PATIENTS

Eighty-three children with CPP (77 girls) and 61 patients with IHH (40 men) were studied. The control group consisted of 200 individuals with normal pubertal development.

METHODS

The promoter region and the three exons of KISS1 were amplified and sequenced. Cells expressing KISS1R were stimulated with synthetic human wild-type or mutant kisspeptin-54 (kp54), and inositol phosphate accumulation was measured. In a second set of experiments, kp54 was preincubated in human serum before stimulation of the cells.

RESULTS

Two novel KISS1 missense mutations, p.P74S and p.H90D, were identified in three unrelated children with idiopathic CPP. Both mutations were absent in 400 control alleles. The p.P74S mutation was identified in the heterozygous state in a boy who developed CPP at 1 yr of age. The p.H90D mutation was identified in the homozygous state in two unrelated girls with CPP. In vitro studies revealed that the capacity of the P74S and H90D mutants to stimulate IP production was similar to the wild type. After preincubation of wild-type and mutant kp54 in human serum, the capacity to stimulate signal transduction was significantly greater for P74S compared with the wild type, suggesting that the p.P74S variant is more stable. Only polymorphisms were found in the IHH group.

CONCLUSION

Two KISS1 mutations were identified in unrelated patients with idiopathic CPP. The p.P74S variant was associated with higher kisspeptin resistance to degradation in comparison with the wild type, suggesting a role for this mutation in the precocious puberty phenotype.

Molecular analysis of CYP21A2 can optimize the follow-up of positive results in newborn screening for congenital adrenal hyperplasia

Neonatal screening for congenital adrenal hyperplasia (CAH) is useful in diagnosing salt wasting form (SW). However, there are difficulties in interpreting positive results in asymptomatic newborns. The main objective is to analyze genotyping as a confirmatory test in children with neonatal positive results. Patients comprised 23 CAH children and 19 asymptomatic infants with persistently elevated 17-hydroxyprogesterone (17OHP) levels. CYP21A2 gene was sequenced and genotypes were grouped according to the enzymatic activity of the less severe allele: A1 null, A2 < 2%, B 3-7%, C > 20%. Twenty-one children with neonatal symptoms and/or 17OHP levels > 80 ng/ml carried A genotypes, except two virilized girls (17OHP < 50 ng/ml) without CAH genotypes. Patients carrying SW genotypes (A1, A2) and low serum sodium levels presented with neonatal 17OHP > 200 ng/ml. Three asymptomatic boys carried simple virilizing genotypes (A2 and B): in two, the symptoms began at 18 months; another two asymptomatic boys had nonclassical genotypes (C). The remaining 14 patients did not present CAH genotypes, and their 17OHP levels were normalized by 14 months of age. Molecular analysis is useful as a confirmatory test of CAH, mainly in boys. It can predict clinical course, identify false-positives and help distinguish between clinical forms of CAH.

Ectopic ACTH syndrome caused by pheochromocytoma: computed tomography-guided percutaneous ethanol injection as an alternative treatment

Ectopic ACTH secretion represents 8-18% of the cases of endogenous hypercortisolism. Pheochromocytomas correspond to 2-25% of the cases and surgery is the indicated treatment. We describe a case of ACTH-secreting pheochromocytoma treated with percutaneous ethanol injection (PEI) guided by computed tomography (CT). A 71-yr-old man presented with diabetes, severe hypokalemia, weight loss, muscle weakness, and hypertension. Hormonal evaluation revealed elevated levels of urinary cortisol, ACTH, catecholamines, and urinary metanephrines. There was no cortisol or ACTH response to desmopressin stimulation test. Magnetic resonance revealed bilateral adrenal nodules, larger on the left side. The suspected diagnosis was ectopic ACTH syndrome caused by pheochromocytoma. Ketoconazole treatment resulted in reduction of urinary cortisol levels but was followed by severe cholestasis and hepatic dysfunction, preventing surgery; it was substituted by octreotide with reduction of ACTH and cortisol levels, but without improvement of cholestasis. The patient presented cachexia and developed multiple pulmonary abscesses that also prevented surgical treatment, thus he was treated with percutaneous ethanol injection guided by CT of the left adrenal tumor. During the procedure, the patient had an increase in blood pressure controlled by the infusion of sodium nitroprusside followed by hypotension that required infusion of dopamine and volume expansion. Afterwards, he presented hormonal normalization, normal catecholamines levels, and clinical improvement. Histological tissue analysis confirmed pheochromocytoma. We concluded that CT-guided PEI represents an efficient alternative therapy to ectopic ACTH-secreting pheochromocytomas in patients without clinical conditions for surgery.

Height and bone mineral density in androgen insensitivity syndrome with mutations in the androgen receptor gene

INTRODUCTION AND HYPOTHESIS

Androgen insensitivity syndrome (AIS) constitutes a natural model to study effects of androgens and estrogens on growth and bone density. We evaluated height and bone density in patients with AIS with mutations in the androgen receptor (AR) gene.

METHODS

A retrospective analysis was conducted of eight subjects with complete AIS (CAIS) and four with partial AIS (PAIS) submitted to gonadectomy followed by estrogen replacement, and three with PAIS who did not undergo gonadectomy. Standing height and bone mineral apparent density (BMAD) by DXA were measured and compared with male (z (m)) and female (z (f)) reference populations. The z-scores were compared with a value of zero using the one-sample t-test.

RESULTS

Final heights of patients with CAIS and PAIS were intermediate between those predicted for females and males. BMAD of the lumbar spine in CAIS and PAIS after gonadectomy and estrogen replacement (z (f) = - 1.56 +/- 1.04, P = 0.006, and z (m) = - 0.75 +/- 0.89, P = 0.04) indicated vertebral bone deficit, whereas BMAD at the femoral neck was normal. No patient reported fractures.

CONCLUSION

Subjects with AIS had mean final height intermediate between mean normal male and female, and decreased bone mineral density in the lumbar spine. These data suggest an important role for androgens in normal male growth and bone density not replaced by estrogens.

Reproductive outcome of women with 21-hydroxylase-deficient nonclassic adrenal hyperplasia

CONTEXT

Because many women with 21-hydroxylase (21-OH)-deficient nonclassic adrenal hyperplasia (NCAH) carry at least one allele affected by a severe mutation of CYP21, they are at risk for giving birth to infants with classic adrenal hyperplasia (CAH).

OBJECTIVE

Our objective was to determine the frequency of CAH and NCAH infants born to mothers with 21-OH-deficient NCAH.

DESIGN AND SETTING

We conducted an international multicenter retrospective/prospective study.

PATIENTS AND METHODS

The outcome of 203 pregnancies among 101 women with 21-OH-deficient NCAH was reviewed. The diagnosis of 21-OH-deficient NCAH was established by a basal or post-ACTH-stimulation 17-hydroxyprogesterone level of more than 10 ng/ml (30.3 nmol/liter). When possible, genotype analyses were performed to confirm CAH or NCAH in the offspring.

RESULTS

Of the 203 pregnancies, 138 (68%) occurred before the mother's diagnosis of NCAH and 65 (32%) after the diagnosis. Spontaneous miscarriages occurred in 35 of 138 pregnancies (25.4%) before the maternal diagnosis of NCAH, and in only four of 65 pregnancies (6.2%) after the diagnosis (P < 0.002). Four (2.5%; 95% confidence interval, 0.7-6.2%) of the 162 live births were diagnosed with CAH. To date, 24 (14.8%; 95% confidence interval, 9.0-20.6%) children, 13 girls and 11 boys, have been diagnosed with NCAH. The distribution of NCAH children and their mothers varied significantly by ethnicity (P < 0.0001, for both).

CONCLUSIONS

The risk of a mother with 21-OH-deficient NCAH for giving birth to a child affected with CAH is 2.5%; at least 14.8% of children born to these mothers have NCAH.

Combined pituitary hormone deficiency (CPHD) due to a complete PROP1 deletion

OBJECTIVE

PROP1 mutations are the most common cause of genetic combined pituitary hormone deficiency (CPHD). The aim of this study was to investigate the PROP1 gene in two siblings with CPHD.

DESIGN

Pituitary function and imaging assessment and molecular analysis of PROP1.

PATIENTS

Two siblings, born to consanguineous parents, presented with GH deficiency associated with other pituitary hormone deficiencies (TSH, PRL and gonadotrophins). The male sibling also had an evolving cortisol deficiency.

METHODS

Pituitary size was evaluated by magnetic resonance imaging (MRI). PROP1 gene analysis was performed by polymerase chain reaction (PCR), automatic sequencing and Southern blotting. Amplification of sequence tag sites (STS) and the Q8N6H0 gene flanking PROP1 were performed to define the extension of PROP1 deletion.

RESULTS

MRI revealed a hypoplastic anterior pituitary in the girl at 14 years and pituitary enlargement in the boy at 18 years. The PROP1 gene failed to amplify in both siblings, whereas other genes were amplified. Southern blotting analysis revealed the PROP1 band in the controls and confirmed complete PROP1 deletion in both siblings. The extension of the deletion was 18.4 kb. The region flanking PROP1 contains several Alu core sequences that might have facilitated stem-loop-mediated excision of PROP1.

CONCLUSIONS

We report here a complete deletion of PROP1 in two siblings with CPHD phenotype.

Inhibin alpha-subunit (INHA) gene and locus changes in paediatric adrenocortical tumours from TP53 R337H mutation heterozygote carriers

The R337H TP53 mutation is a low-penetrance molecular defect that predisposes to adrenocortical tumour (ACT) formation in Brazilian and possibly other populations. Additional genetic defects may be responsible for the variable expression of ACTs in these cases. The inhibin alpha-subunit gene (INHA) on 2q33-qter has been implicated in mouse adrenocortical tumourigenesis. We studied 46 pediatric patients with ACTs from Brazil for INHA genetic alterations; 39 of these patients were heterozygous carriers of the R337H TP53 mutation. We first mapped the INHA gene by radiation hybrid analysis and determined 10 linked microsatellite markers in an area flanked by D2S1371 and D2S206 on 2q33-qter. These markers were then used for loss of heterozygozity (LOH) studies in nine paired germline and tumour DNA samples. Mapping placed the INHA gene in close proximity to D2S2848 (SHGC11864) with a log of odds (LOD) score of 5.84. LOH for at least one marker in the region was identified in 8/9 tumours (89%). Six patients were heterozygous for three INHA mutations: one in exon 1, 127C>G, and two in exon 2, 3998G>A and 4088G>A, all leading to amino acid substitutions (P43A, G227R, and A257T, respectively). A257T is located in a conserved INHA region, highly homologous to transforming growth factor-beta; both G227R and A257T change polarity, and, in addition, G227R changes the pH. We conclude that these sequence alterations and the detected 2q allelic changes suggest that INHA may be one of the contributing factors needed for ACT formation in pediatric patient carriers of the R337H TP53 mutation.

Mutations in the SRY, DAX1, SF1 and WNT4 genes in Brazilian sex-reversed patients

In most mammals, male development is triggered by the transient expression of the SRY gene, which initiates a cascade of gene interactions ultimately leading to the formation of a testis from the indifferent fetal gonad. Mutation studies have identified several genes essential for early gonadal development. We report here a molecular study of the SRY, DAX1, SF1 and WNT4 genes, mainly involved in sexual determination, in Brazilian 46,XX and 46,XY sex-reversed patients. The group of 46,XX sex-reversed patients consisted of thirteen 46,XX true hermaphrodites and four 46,XX males, and was examined for the presence of the SRY gene and for the loss of function (inactivating mutations and deletions) of DAX1 and WNT4 genes. In the second group consisting of thirty-three 46,XY sex-reversed patients we investigated the presence of inactivating mutations in the SRY and SF1 genes as well as the overexpression (duplication) of the DAX1 and WNT4 genes. The SRY gene was present in two 46,XX male patients and in none of the true hermaphrodites. Only one mutation, located outside homeobox domain of the 5' region of the HMG box of SRY (S18N), was identified in a patient with 46,XY sex reversal. A novel 8-bp microdeletion of the SF1 gene was identified in a 46,XY sex-reversed patient without adrenal insufficiency. The dosage of DAX1 and WNT4 was normal in the sex-reversed patients studied. We conclude that these genes are rarely involved in the etiology of male gonadal development in sex-reversed patients, a fact suggesting the presence of other genes in the sex determination cascade.

Clinical and molecular analysis of human reproductive disorders in Brazilian patients

Several genes that influence the development and function of the hypothalamic-pituitary-gonadal-axis (HPG) have been identified. These genes encode an array of transcription factors, matrix proteins, hormones, receptors, and enzymes that are expressed at multiple levels of the HPG. We report the experience of a single Endocrinology Unit in the identification and characterization of naturally occurring mutations in families affected by HPG disorders, including forms of precocious puberty, hypogonadism and abnormal sexual development due to impaired gonadotropin function. Eight distinct genes implicated in HPG function were studied: KAL, SF1, DAX1, GnRH, GnRHR, FSHbeta, FSHR, and LHR. Most mutations identified in our cohort are described for the first time in literature. New mutations in SF1, DAX1 and GnRHR genes were identified in three Brazilian patients with hypogonadism. Eight boys with luteinizing hormone- (LH) independent precocious puberty due to testotoxicosis were studied, and all have their LH receptor (LHR) defects elucidated. Among the identified LHR molecular defects, three were new activating mutations. In addition, these mutations were frequently associated with new clinical and hormonal aspects, contributing significantly to the knowledge of the molecular basis of reproductive disorders. In conclusion, the naturally occurring genetic mutations described in the Brazilian families studied provide important insights into the regulation of the HPG.

Glucocorticoid receptor gene polymorphisms in ACTH-secreting pituitary tumours

OBJECTIVE

The inhibitory action of glucocorticoids on the hypothalamic-pituitary axis is disrupted in ACTH-secreting pituitary tumours. The molecular events leading to the development of these tumours and their relative resistance to glucocorticoids are unknown. We investigated the presence of mutations and polymorphisms of the glucocorticoid receptor (GR) gene in corticotropinoma and their possible relationship with the tissue-specific resistance to glucocorticoids.

DESIGN AND METHODS

DNA or RNA was extracted from 18 corticotropinomas and the GR gene was amplified by the polymerase chain reaction (PCR) or reverse transcriptase-PCR followed by automated direct sequencing.

RESULTS

We did not identify any mutation in the coding region and the exon-intron boundary regions of the GR gene. The polymorphism AAT > AGT at codon 363 (N363S) was found in 17% and the polymorphism AAT > AAC at codon 766 (N766N) in 11% of tumours, both in heterozygous state. The polymorphisms at codons 22 and 23, at introns 3 and 4, and at codon 618, previously described in normal population, were not observed.

CONCLUSIONS

Our results show that GR gene mutations are rare and unlikely to contribute to the glucocorticoid resistance observed in corticotropinomas. Polymorphisms in the GR gene might confer a selective advantage to tumorigenesis in corticotropinoma. However, there was no relationship between GR gene polymorphism and clinical presentation, tumour size or surgery outcome, suggesting that tumour growth may not be directly related to alterations of the GR gene structure.

An inherited mutation outside the highly conserved DNA-binding domain of the p53 tumor suppressor protein in children and adults with sporadic adrenocortical tumors

Mutations of the p53 tumor suppressor gene are the single most common genetic alterations in human cancers. Recently, a distinct nucleotide substitution was identified in exon 10 of the p53 gene, leading to an Arg337His mutation in 97% of children with adrenocortical tumors from Southern Brazil. In the present study, we investigated the presence of this mutation in a larger series of 55 patients (37 adults and 18 children) with benign and malignant sporadic adrenocortical tumors. None of the patients had family cancer histories that conformed to the criteria for Li-Fraumeni syndrome. Twenty-one asymptomatic close relatives of patients with p53 mutations and 60 normal unrelated individuals were also studied. The missense Arg337His mutation was identified in 19 patients (14 children and 5 adults), and 8 of 11 cases studied had LOH. Among the 19 patients with the Arg337His mutation, only one boy and three adults showed fatal evolution or recurrent metastases. This mutation was also identified in heterozygous state in asymptomatic first-degree relatives of the patients, indicating that Arg337His mutation was inherited in most cases. In contrast, this mutation was not found in 120 alleles of normal unrelated controls. In conclusion, the germ line Arg337His mutation of p53 protein is present at a high frequency (77.7%) in children with benign or malignant sporadic adrenocortical tumors, but it is not restricted to the pediatric group, since 13.5% of adults with adrenocortical tumors also had this mutation. The presence of this mutation was related to unfavorable prognosis in most of the adults, but not in the children with adrenocortical tumors.

Normal bone density in male pseudohermaphroditism due to 5alpha- reductase 2 deficiency

Bone is an androgen-dependent tissue, but it is not clear whether the androgen action in bone depends on testosterone or on dihydrotestosterone. Patients with 5alpha-reductase 2 deficiency present normal levels of testosterone and low levels of dihydrotestosterone, providing an in vivo human model for the analysis of the effect of testosterone on bone.

OBJECTIVE

To analyze bone mineral density in 4 adult patients with male pseudohermaphroditism due to 5alpha-reductase 2 deficiency.

RESULTS

Three patients presented normal bone mineral density of the lumbar column (L1-L4) and femur neck, and the other patient presented a slight osteopenia in the lumbar column.

CONCLUSION

Patients with dihydrotestosterone deficiency present normal bone mineral density, suggesting that dihydrotestosterone is not the main androgen acting in bone.

Adrenocorticotropin-dependent precocious puberty of testicular origin in a boy with X-linked adrenal hypoplasia congenita due to a novel mutation in the DAX1 gene

Primary adrenal insufficiency is a rare condition in pediatric age, and its association with precocious sexual development is very uncommon. We report a 2-yr-old Brazilian boy with DAX1 gene mutation whose first clinical manifestation was isosexual gonadotropin-independent precocious puberty. He presented with pubic hair, enlarged penis and testes, and advanced bone age. T levels were elevated, whereas basal and GnRH-stimulated LH levels were compatible with a prepubertal pattern. Chronic GnRH agonist therapy did not reduce T levels, supporting the diagnosis of gonadotropin-independent precocious puberty. Testotoxicosis was ruled out after normal sequencing of exon 11 of the LH receptor gene. At age 3 yr he developed clinical and hormonal features of severe primary adrenal insufficiency. The entire coding region of the DAX1 gene was analyzed through direct sequencing. A nucleotide G insertion between nucleotides 430 and 431 in exon 1, resulting in a novel frameshift mutation and a premature stop codon at position 71 of DAX-1, was identified. Surprisingly, steroid replacement therapy induced a clear decrease in testicular size and T levels to the prepubertal range. These findings suggest that chronic excessive ACTH levels resulting from adrenal insufficiency may stimulate Leydig cells and lead to gonadotropin-independent precocious puberty in some boys with DAX1 gene mutations.

Two novel mutations in the gonadotropin-releasing hormone receptor gene in Brazilian patients with hypogonadotropic hypogonadism and normal olfaction

Several point mutations in the GnRH receptor gene have been described in an autosomal recessive form of congenital isolated hypogonadotropic hypogonadism (HH). We investigated 17 Brazilian patients (10 males and 7 females) from 14 different families, with HH and normal olfaction. The diagnosis of HH was based on absent or incomplete sexual development after 17 yr of age associated with low or normal levels of LH in both sexes and low levels of testosterone in males and of estradiol in females. All patients presented with a normal sense of smell in an olfactory specific test. The coding region of the GnRH receptor gene was amplified by PCR and directly sequenced. A novel missense mutation, Arg(139)His, located in the conserved DRS motif at the junction of the third transmembrane and the second intracellular loop of the GnRH receptor was identified in the homozygous state in one female with complete HH. The Arg(139)His mutation completely eliminated detectable GnRH-binding activity and prevented GnRH-induced stimulation of inositol phosphate accumulation in vitro. In another family, a new compound heterozygous mutation (Asn(10)Lys and Gln(106)Arg) was identified in four siblings (two males and two females) with partial HH. The Gln(106)Arg mutation, located in the first extracellular loop, has been previously described, and in vitro analysis indicated that the mutant receptor was able to bind GnRH, but with a reduced affinity. The Asn(10)Lys mutation in the extracellular amino-terminal domain of the receptor also reduced the affinity for GnRH in vitro. In this family we also identified a previously described silent polymorphism at amino acid residue 151 in the second intracellular loop that segregated with the two inactivating mutations of the GnRH receptor. This polymorphism was also found in two unrelated patients with sporadic HH without GnRH receptor loss of function mutations. No mutations were identified in the remaining cases. A good correlation between genotype and phenotype was found in our patients. The woman, who is homozygous for the completely inactivating Arg(139)His mutation, has complete HH with undetectable serum basal LH and FSH levels that failed to respond to GnRH stimulation. In addition, the affected patients who are compound heterozygotes for the Asn(10)Lys/Gln(106)Arg mutations, have partial HH with low serum basal LH levels that were responsive to GnRH stimulation. No clinical or hormonal differences were found between HH patients with and without mutations in the GnRH receptor gene, indicating that these data do not contribute to the identification of HH patients with GnRH receptor mutations. In conclusion, we report the first naturally occurring mutation within the conserved DRS motif of the GnRH receptor in a female with complete HH and a novel compound heterozygous mutation (Asn(10)Lys and Gln(106)Arg) in a family with partial HH, increasing the repertoire of the inactivating mutations of the GnRH receptor.

Adrenal nodules in patients with congenital adrenal hyperplasia due to 21-hydroxylase deficiency: regression after adequate hormonal control

Adrenal nodules have been described in patients with 21-hydroxylase deficiency (21OHD). These nodules are usually considered to be ACTH-dependent, as is the commonly seen diffuse cortical hyperplasia. We evaluated the presence and behavior of adrenal nodules in patients with 21OHD. Based upon hormonal status and treatment compliance, the patients were classified into three categories: poor, regular and good control. Out of the 26 patients, eight had the non-classic, four salt-wasting and 14 simple virilizing forms. All patients underwent initial adrenal morphological studies, either by CT or MRI. Those with nodules were reevaluated after 12 months of adequate replacement therapy. Nodules were found in four of eight untreated patients and two of three patients with poor hormonal control, but not in the 15 patients with regular or good control. Adrenal nodules in these six patients demonstrated a considerable size reduction and even disappearance after adequate replacement therapy, showing that these nodules were ACTH-dependent. Thus, six out of 26 patients with 21OHD presented adrenal nodules, which were more frequent in the untreated or poorly-controlled patients, and all regressed in size after adequate therapy.

Molecular analysis of SRY gene in Brazilian 46,XX sex reversed patients: absence of SRY sequence in gonadal tissue

BACKGROUND

The importance of the Y chromosome in male determination has been well established for a long time. The presence of a translocation of chromosomal material encoding the Testis-Determining Factor from Y to another chromosome has been one of the hypothesis to explain testicular development in XX sex-reversed patients.

MATERIAL AND METHODS

In the present study, we searched for SRY sequence in genomic DNA isolated from peripheral leukocytes in eleven 46,XX true hermaphrodites and four 46,XX males (only one with ambiguous genitalia). We also analyzed the presence of SRY sequence in fresh gonadal tissues from two 46,XX true hermaphrodites.

RESULTS

SRY sequence was absent in DNA blood samples of all true hermaphrodites and in testicular and ovarian tissues of two cases studied. Of the four 46,XX males, two with normal male external genitalia were SRY positive.

CONCLUSIONS

We did not identify the SRY gene in 46,XX true hermaphrodites and 46,XX males with ambiguous genitalia, therefore SRY translocation to X chromosome or autosome is unlikely. Hidden Y mosaicism in gonadal tissues was also ruled out in two cases, suggesting that cryptic SRY mosaicism in gonadal tissues is not the usual mechanism responsible for testicular development in patients with 46,XX true hermaphroditism. However, SRY gene was identified in two 46,XX males with male external genitalia showing that SRY gene determined their male phenotype. Despite the recent advances in the knowledge of the role of several genes involved in sexual determination we are still unable to explain the cause of most of Y-chromosome-negative 46,XX sex-reversed patients.

21-Hydroxylase-deficient nonclassic adrenal hyperplasia is a progressive disorder: a multicenter study

OBJECTIVE

Our aim was to determine whether the clinical features of 21-hydroxylase-deficient nonclassic adrenal hyperplasia are correlated with either age at symptom onset or age at presentation, or both, and with the degree of adrenocortical abnormality.

STUDY DESIGN

In a multicenter cohort design 220 women with nonclassic adrenal hyperplasia, with a basal or adrenocorticotropic hormone-stimulated 17-hydroxyprogesterone level >30.3 nmol/L, were studied, either prospectively (n = 39) or retrospectively (n = 181). Patients were stratified by age of presentation into 5 groups: (1) <10 years (n = 25), (2) 10 to 19 years (n = 64), (3) 20 to 29 years (n = 83), (4) 30 to 39 years (n = 30), and (5) 40 to 49 years (n = 16). Two patients >50 years old were excluded from the analysis because of age.

RESULTS

Ninety-two percent of patients <10 years old had premature pubarche at presentation, whereas clitoromegaly and acne were each present in only 20% of these younger subjects. With only patients > or =10 years old considered, presenting clinical features included hirsutism (59%), oligomenorrhea (54%), acne (33%), infertility (13%), clitoromegaly (10%), alopecia (8%), primary amenorrhea (4%), and premature pubarche (4%). Among the patients >/=10 years old, the prevalence but not the degree of hirsutism increased significantly with age. Basal levels of 17-hydroxyprogesterone in adolescents were significantly higher than the levels found either in children (<10 years old) or women 40 to 49 years old (P <.01 and P <.03, respectively), although no difference was noted in the stimulated 17-hydroxyprogesterone levels between age groups. The adrenocorticotropic hormone-stimulated levels but not the basal levels of 17-hydroxyprogesterone were significantly higher in patients with clitoromegaly than in women without clitoromegaly. Alternatively, there were no differences in either basal or stimulated 17-hydroxyprogesterone levels between patients with and those without hirsutism, acne, or alopecia.

CONCLUSION

In children <10 years old the most common presenting complaint was premature pubarche, whereas hirsutism and oligomenorrhea were more common in older patients. The prevalence of hirsutism increased with age, suggesting the progressive nature of nonclassic adrenal hyperplasia. Furthermore, the adrenocorticotropic hormone-stimulated levels of 17-hydroxyprogesterone were higher in patients with clitoromegaly, which suggests that the degree of adrenocortical dysfunction in nonclassic adrenal hyperplasia determines, at least in part, the clinical presentation.

Gonadotropin-independent precocious puberty due to luteinizing hormone receptor mutations in Brazilian boys: a novel constitutively activating mutation in the first transmembrane helix

Naturally occurring activating mutations in the human LH receptor (hLHR) gene are the cause of sporadic or familial male gonadotropin-independent precocious puberty. We have previously reported three different activating mutations of the hLHR gene in four unrelated Brazilian boys with male-limited precocious puberty. In the current study, we examined three other Brazilian boys, two brothers and one unrelated boy, with gonadotropin-independent precocious puberty. Direct sequencing of the entire exon 11 of the hLHR gene in the two brothers revealed a heterozygous substitution of T for C at nucleotide 1103, resulting in the substitution of leucine at position 368 by proline in the first transmembrane helix. Their mother carried the same mutation, establishing the familial nature of this mutation. Human embryonic 293 cells expressing hLHR(L368P) bound hCG with the same high affinity as cells expressing the wild-type hLHR. Cells expressing the novel L368P mutation displayed up to a 12-fold increase in basal cAMP production compared with cells expressing the same number of cell surface wild-type hLHR, indicating constitutive activation of the mutant receptor. In addition, the cAMP levels in cells expressing the hLHR mutant were further augmented by hCG. Molecular dynamics simulations suggest that substitution of L368 of the hLHR by proline results in lack of a salt bridge interaction between D405 and R464 (distance 9. 0 A vs. 4.7 A in wild-type hLHR) as well as by the opening of a crevice between the second and third intracellular loops, which may allow G proteins greater accessibility. These structural features were shared by other activating mutants of the hLHR. Sequencing of exon 11 of the hLHR gene of the unrelated boy revealed that he carried a homozygous nucleotide substitution causing an A568V mutation in the third cytoplasmic loop of the receptor. This mutation was previously found in two unrelated Brazilian boys, but in heterozygous state. Clinical and hormonal data of the patient with the homozygous A568V were not different from those individuals with the Ala568Val mutation in a heterozygous state. Furthermore, the phenotype caused by dominant activating mutations of the hLHR gene are not altered when both alleles carry a mutant sequence. Our studies show that the A568V is the most frequent cause of male-limited precocious puberty in Brazilian boys. Lastly, the identification of a novel activating L368P mutation in the first transmembrane helix of two Brazilian boys with familial male-limited precocious puberty provides further insights into the mechanism of activation of the hLHR.

The effect of distinct activating mutations of the luteinizing hormone receptor gene on the pituitary-gonadal axis in both sexes

OBJECTIVE

Familial or sporadic male-limited precocious puberty is a distinct and unusual gonadotrophin-independent form of sexual precocity caused by constitutively activating mutations of the luteinizing hormone receptor (LHR). In the present study, we evaluated the effect of known activating mutations at different sites of the LHR gene on the pituitary-gonadal axis in both sexes.

PATIENTS

Four unrelated Brazilian boys (I-IV) with gonadotrophin-independent precocious puberty and two asymptomatic females (V-VI), a sister and mother of two of the affected boys, were studied. Patients I, II and V carried the Ala568Val mutation located at the third intracellular loop of the LHR. Patient III carried the Leu457Arg mutation at the third transmembrane helix, and patients IV and VI carried the Thr577Ile mutation at the sixth transmembrane helix of the LHR.

MEASUREMENTS

Serum levels of LH, FSH, testosterone, and oestradiol under basal and GnRH-stimulated conditions were determined in all patients. Testosterone levels were also measured after a hCG stimulation test in patient III.

RESULTS

Basal LH and FSH levels were prepubertal in all boys studied. The GnRH-stimulated serum LH and FSH levels were prepubertal in three boys (I, II and IV), whereas patient III showed totally suppressed LH and FSH levels at ages 2 and 7 years (bone ages 6 and 14 years, respectively). Serum testosterone levels ranged from 3.8 to 69.5 nmol/l in the four boys. Patient III had the highest testosterone levels that did not respond to hCG stimulation. The 4 year-old girl (patient V) was phenotypically normal and the acute response to GnRH was indicative of prepubertal status. Patient VI had normal menstrual cycles and fertility.

CONCLUSIONS

These findings indicate variable effects of LHR activating mutations on the pituitary-gonadal axis in boys that can result in lack of normal LH and FSH release. In contrast, prepubertal and adult females were asymptomatic and had normal basal and GnRH-stimulated LH and FSH levels.

Male pseudohermaphroditism due to 17 beta-hydroxysteroid dehydrogenase 3 deficiency. Diagnosis, psychological evaluation, and management

Ten male pseudohermaphrodites with 17 beta-hydroxysteroid dehydrogenase 3 (17 beta-HSD3) deficiency were evaluated in 1 clinic with an average follow-up of 10.1 years. The diagnoses were made by demonstrating low to normal serum testosterone levels, high androstenedione levels, and high ratios of serum androstenedione to testosterone in the basal state or after treatment with human chorionic gonadotropin. The molecular features of the underlying mutations were identified in all 7 families. Two additional males in the same families are believed to be affected on the basis of history obtained from family members. All of the 46,XY individuals in these families were registered at birth and raised as females (despite the presence of ambiguous genitalia in all or most), and all virilized after the time of expected puberty due to a rise in serum testosterone to or toward the normal male range. The age at diagnosis varied from 4 to 37 years. Ten individuals were studied by the same psychologist, and change of gender role (social sex) from female to male occurred in 3 subjects and in the 2 presumed affected subjects not studied. The individual with the highest serum testosterone level maintained female sexual identity, and in 2 families some of the affected males changed gender role and others did not. Thus, while androgen action plays a role in the process, additional undefined psychological, social, and/or biologic factors must be determinants of gender identity/role behavior. Management of the 7 individuals who chose to maintain female sex roles included castration, clitoroplasty, vaginal enlargement procedures when appropriate, treatment of hirsutism, cricoid cartilage reduction, and estrogen replacement. Three of the 7 are married (2 twice), 1 is involved in a long-term heterosexual relationship, 1 is engaged to be married, and the other 2 are not married and not believed to be sexually active. The 3 subjects who changed gender role behavior to male underwent hypospadias repair, and 1 was given supplemental testosterone therapy. One of these men is divorced, and the other 2 (aged 29 and 35 years) are unmarried. The diagnosis in 8 of these subjects was made after the time of expected puberty; it is unclear whether the functional and social outcomes would have been different if the diagnosis had been made and therapy begun earlier in life.

Genotyping of the type II 3beta-hydroxysteroid dehydrogenase gene (HSD3B2) in women with hirsutism and elevated ACTH-stimulated delta(5)-steroids

OBJECTIVE

Genotyping of the HSD3B2 gene in females with hirsutism and elevated ACTH-stimulated Delta(5)-steroids.

DESIGN

Fourteen adult females whose ACTH-stimulated 17-hydroxypregnenolone (17OH-PREG) levels were elevated (>/= 2.3 SD).

SETTING

University hospital outpatient clinic and molecular endocrinology laboratory.

PATIENT(S)

Thirteen women with hirsutism and one with virilization.

INTERVENTION(S)

ACTH-stimulation test and genotyping of the HSD3B2 gene.

MAIN OUTCOME MEASURE(S)

The four exons and exon-intron boundaries of the HSD3B2 gene were amplified by the use of polymerase chain reaction and were screened for mutations by denaturing gradient gel electrophoresis. The fragments that were found to have abnormal migration on denaturing gradient gel electrophoresis were directly sequenced.

RESULT(S)

No mutations were found in 13 patients who had mild to moderate elevations in ACTH-stimulated 17OH-PREG levels, and the T259M mutation was identified in the woman with virilization and extremely high 17OH-PREG levels.

CONCLUSION(S)

Mutations in the HSD3B2 gene were not found in women with hirsutism and mild-to-moderate elevations in ACTH-stimulated 17OH-PREG levels.

Combined pituitary hormone deficiency caused by a novel mutation of a highly conserved residue (F88S) in the homeodomain of PROP-1

Mutations in the pituitary-specific paired-like homeodomain transcription factor, PROP-1, result in combined pituitary hormone deficiency. We studied a Brazilian girl, offspring of first cousins, who presented with short stature and deficiencies of GH, TSH, PRL, LH, and FSH. Her cortisol response to hypoglycemia was determined at age 4.9, 10.7, and 14.1 yr and remained normal. Magnetic resonance imaging at the age of 9 yr revealed an anterior pituitary lobe of diminished height (3 mm; normal, 4.5 +/- 0.6), but radiography revealed a sella turcica volume above the normal mean. Direct sequencing of the PROP-1 gene revealed homozygosity for a novel 263T>C transition that results in the replacement of a highly conserved phenylalanine by serine at codon 88 (F88S). F88 constitutes the hydrophobic core of the first helix of the homeodomain of PROP-1, and the substitution by the polar residue serine is expected to alter the secondary structure and impair binding of the mutated PROP-1 to DNA target sequences. The F88S mutation (which corresponds to murine F85S) was introduced into the murine Prop-1 complementary DNA and its consequences on DNA binding and trans-activation were assessed in vitro. In contrast to wild-type Prop-1, the F88S mutant showed no significant DNA binding to a PRDQ9 Prop-1 response element in gel shift assays. Transcriptional activation of a luciferase reporter gene containing a PRDQ9 site upstream of a simian virus 40 promoter was reduced to approximately 34% compared with that of wild-type Prop-1 in transiently transfected TSA-201 human embryonic kidney cells. The F88S mutation further expands the repertoire of mutations in PROP-1.

A novel homozygous nonsense mutations E135* in the type II 3beta-hydroxysteroid dehydrogenase gene in a girl with salt-losing congenital adrenal hyperplasia. Mutations in brief no. 168. Online

Mutations in the 3beta-hydroxysteroid dehydrogenase (3beta-HSD) type II gene have been reported in a small number of affected females. We report a 46,XX girl born to consanguineous parents from Chile. At birth, she had normal but hyperpigmented female external genitalia. At 60 days she presented salt loss. At 20 months, the diagnosis of classic salt-losing 3beta-HSD deficiency was made based on an elevated serum 17-hydroxpregnenolone concentration and a high 17 hydroxypregnenolone/17-hydroxyprogesterone ratio. Genomic DNA was amplified by PCR and screened for mutations by denaturing gradient gel electrophoresis and directly sequenced. A novel homozygous E135* mutation was found in the 3beta-HSD type II gene of the patient while her parents were heterozygotes. This novel nonsense homozygous E135* mutation led to encode a predicted truncated 134 amino acid protein instead of the native 371 amino acid 3beta-HSD type II protein. This predicted product is consistent with the severe 3beta-HSD deficiency in this girl.

Influence of different genotypes on 17-hydroxyprogesterone levels in patients with nonclassical congenital adrenal hyperplasia due to 21-hydroxylase deficiency

OBJECTIVE

The diagnosis of the nonclassical form of 21-hydroxylase (NC-21OH) deficiency, established before molecular studies, is based on basal 17OH-progesterone (17OH-P) values > 15 nmol/l or ACTH-stimulated 17OH-P values > 30 nmol/l. This disease is caused by mutations in the structural gene that can be grouped into three categories: A, B and C, according to the predicted level of enzymatic activity. So, the genotype of the nonclassical form is a combination of mutations that cause moderate impairment of enzymatic activity in one allele and mutations which cause total (A), severe (B: 3%) or moderate (C: 20-60%) impairment of enzymatic activity in the other allele.

DESIGN

We analysed the influence of the different genotypes on 17OH-P levels in 58 patients with the nonclassical form of 21OH deficiency.

RESULTS

After screening for 18 mutations through Southern blotting, allele-specific polymerase chain reaction (PCR) and enzyme restriction, mutations were identified in 73% of the alleles. Patients with mutations identified in both alleles were divided into groups A/C (n = 18), B/C (n = 3) and C/C (n = 15). The basal and ACTH-stimulated 17OH-P levels in patients with A/C genotype ranged from 1.2 to 153 and 72-363 nmol/l, and in C/C genotype ranged from 0.9 to 72 and 51-363 nmol/l, respectively (P < 0.05 for stimulated levels). The lowest value of ACTH-stimulated 17OH-P levels in fully genotyped patients was 51 nmol/l. Patients with the A/C genotype presented androgen excess symptoms earlier than patients with the C/C genotype.

CONCLUSIONS

These data suggest an influence of genotype on phenotype and on 17OH-P levels. The high frequency of unidentified mutant alleles in nonclassical 21-hydroxylase deficiency suggests that ACTH-stimulated values of 17OH-P between 30 and 51 nmol/l have overestimated this diagnosis. Genotyping more patients with nonclassical 21-hydroxylase deficiency will help to redefine the cut-off value for ACTH-stimulated 17OH-P for correct diagnosis of this disease.

Lack of reduction in body fat after treatment with insulin-like growth factor-I in two children with growth hormone gene deletions

Two patients with growth hormone (GH) gene deletions were treated with recombinant insulin-like growth factor-I (IGF-I) (80-240 (microg/kg/day) and the effects on bone mass and body composition were compared to administration of GH (0.075 U/kg/day) to 8 patients with idiopathic GH deficiency. Bone mass and body composition were measured by dual photon X-ray absorptiometry (DEXA ) before and 3 and 6 months after treatment with GH or IGF-I. Similar increases in growth velocities were observed after GH and IGF-I treatment. Treatment with GH resulted in prompt and significant reduction in body fat percentage (basal, 3 and 6 months: 22+/-10, 17+/-9, and 16+/-9%) whereas body fat percentage remained unchanged after IGF-I therapy (basal, 3 and 6 months: 49, 52 and 48% in patient 1 and 45, 42 and 43% in patient 2, respectively). Fat percentage remained elevated after 18 months of IGF-I treatment in patients 1 (51%) and 2 (44%), respectively. Lean mass and bone mineral content increased with GH and IGF-I therapies. We conclude that reduction of body fat measured by DEXA, observed after administration of GH but not after IGF-I treatment in these children with GH deficiency, suggests that the GH effect on body fat mass is not mediated by circulating IGF-I.

Origin of an ovarian steroid cell tumor causing isosexual pseudoprecocious puberty demonstrated by the expression of adrenal steroidogenic enzymes and adrenocorticotropin receptor

Ovarian steroid cell tumors are rare neoplasms composed of typical steroid hormone-secreting cells. Most ovarian steroid cell tumors, however, cannot be appropriately classified on a morphological basis, because the neoplastic cells closely resemble adrenal cortical cells. Nevertheless, the true adrenal origin of such tumors has been difficult to demonstrate. Here we report a 3-yr-old girl with isosexual pseudoprecocious puberty due to an ovarian steroid tumor whose adrenal cell origin was determined by the presence of messenger ribonucleic acid (mRNA) of adrenal-specific steroidogenic P450 enzymes (P450c11 and P450c21) and ACTH receptor (ACTHR). Her height was +2.3 SD, and she had Tanner stage III breast development, Tanner stage II pubic hair, and a normal clitoris. Bone age was 5 yr. Basal gonadotropin levels were undetectable (<0.6 U/L for LH and <1.0 U/L for FSH) and remained undetectable after stimulation with 100 microg GnRH, i.v. Basal serum testosterone and 17-hydroxyprogesterone levels were slightly elevated, whereas basal serum androstenedione, estradiol, and dehydroepiandrosterone sulfate levels were clearly elevated. Pelvic ultrasound disclosed an enlarged uterus and an adnexal multicystic mass in the right ovary, and pathological studies disclosed an ovarian steroid cell tumor. To establish the cellular origin of the tumor we determined the presence of mRNA for P450c11, P450c21, and ACTHR in tumor tissue and normal adrenal and ovarian tissue. Detection of ACTHR, P450c21, and P450c11 mRNAs isoforms was achieved in tumoral and adrenal control tissue, but not in the ovary control tissue. The RT-PCR products of P450c11 from adrenal control tissue were composed by both BglI-sensitive and -resistant complementary DNAs, indicating the presence of both P450c11AS and P450c11beta, whereas RT-PCR product from the tumor was resistant to BglI digestion, indicating only the presence of P450c11beta. We conclude that the histological origin of so-called adrenal rest tumor could be reliably determined by assessing the expression of specific genes in the tumor as P450c11beta and P450c21. The use ofthese molecular tools will allow a more precise classification of an important subset of the ovarian steroid cell tumors and can help to identify ectopic adrenal tissue in ovary and testis.

Phenotypic variability and origins of mutations in the gene encoding 3beta-hydroxysteroid dehydrogenase type II

Mutations in HSD3B2, the gene for 3beta-hydroxysteroid dehydrogenase type II (3beta-HSD II) have been detected and activities analysed through the in vitro expression of mutant cDNAs. Two full sibs with male pseudohermaphroditism were found to be double heterozygotes: N100S/266DeltaA. This genotype leads to the most profound loss of 3beta-HSD II enzyme activity (1.3% of normal) described to date in cases without severe salt-loss. One sib (N100S/266DeltaA) is the first reported male case of type II deficiency affected with premature adrenarche. Three apparently independent kindreds had propositi affected with the HSD3B2 mutation A82T/A82T, which is associated with a non salt-losing phenotype with variable expressivity in females. These three families had the same extended HSD3B haplotype and are likely to have inherited the same ancestral mutation. The significance of this finding is discussed in the light of the presence of A82T mutation at a homologous position in pseudogene varphi5 that is present in the HSD3B cluster.

Mutations in the type II 3beta-hydroxysteroid dehydrogenase (HSD3B2) gene can cause premature pubarche in girls

OBJECTIVE

Most previous studies have failed to demonstrate any mutations in the type II 3beta hydroxysteroid dehydrogenase (HSD3B2) gene in patients satisfying the hormonal criteria of nonclassic 3beta-hydroxysteroid dehydrogenase deficiency, suggesting that a mutant 3beta-hydroxysteroid dehydrogenase protein is not the cause of this disorder. We screened the HSD3B2 gene for mutations in girls with premature pubarche and a hormonal diagnosis of 3beta-hydroxysteroid dehydrogenase deficiency.

DESIGN

From 30 girls with premature pubarche, we selected 9 whose ACTH-stimulated 17-hydroxypregnenolone levels were elevated (> or =6 SD) and screened the HSD3B2 gene for mutations.

MEASUREMENTS

All patients were submitted to a standard ACTH stimulation test. Serum steroids were measured and compared to the mean level of pubertal stage matched control subjects. The four exons and exon-intron boundaries of the HSD3B2 gene were amplified by polymerase chain reaction and screened for mutations by denaturing gradient gel electrophoresis. The fragments with abnormal migration on denaturing gradient gel electrophoresis were directly sequenced.

RESULTS

A homozygous T259M mutation was identified in one girl and a new compound heterozygous G129R/P222H mutation was identified in two sisters. The highest ACTH-stimulated 17-hydroxypregnenolone levels, 147, 339 and 351 nmol/l, were found in those patients with mutations in the HSD3B2 gene. In the patients without mutations, ACTH-stimulated 17-hydroxypregnenolone ranged from 48 to 111 nmol/l. ACTH-stimulated dehydroepiandrosterone levels had an overlap among the girls with and without mutations and the normal controls.

CONCLUSIONS

Premature pubarche can be caused by mutations in the type II 3beta hydroxysteroid dehydrogenase gene.

Clinical features of women with resistance to luteinizing hormone

OBJECTIVE

To review clinical and hormonal characteristics of new and published females with LH resistance.

PATIENTS

Seven sisters of patients with male pseudohermaphroditism due to LH resistance.

MEASUREMENTS

Clinical characteristics, hormonal levels, pelvic ultrasound and molecular studies.

RESULTS

Patients had: (1) normal female external genitalia; (2) spontaneous breast and pubic hair development at ages 9-13 years; (3) menarche at 12-20 years, followed by irregular menstrual cycles (3 weeks to 15 months); (4) infertility; (5) withdrawal bleeding after progesterone administration; (6) elevated serum LH levels (10-38 IU/l, normal 0. 9-8.4) and elevated LH/FSH ratio with normal androgen levels; (7) low or normal oestradiol levels for the follicular phase; and (8) normal or small uterus and normal or increased ovary size with one or more cysts at ultrasound examination. Ovarian biopsy showed antral follicles and confirmed lack of ovulation. One homozygous mutation in exon 11 of the LH receptor gene was found in each of 4 patients: 1 nonsense (Arg554Stop) and 2 missense mutations (Glu354Lys and Ala593Pro) and 1 microdeletion (Leu-608, Val-609) were found. In 3 patients (1 family) with the same phenotypic characteristics, no mutations in the coding sequence of the LH receptor gene were found.

CONCLUSIONS

We conclude that women with LH resistance have spontaneous breast development, primary or secondary amenorrhoea, infertility, elevated serum LH levels and LH/FSH ratio with normal androgen levels and normal or enlarged cystic ovaries. Therefore, in females, primary and secondary sexual characteristics develop independently of LH action. However, LH stimulation is necessary for normal ovarian steroidogenesis and ovulation.

Diagnostic value of fluorometric assays in the evaluation of precocious puberty

To establish normative data and determine the value of fluorometric AutoDELFIA assays (Wallac Oy) in the investigation of precocious puberty, we determined serum levels of LH, FSH, testosterone, and estradiol under basal and GnRH-stimulated conditions in 277 normal subjects at various pubertal stages and in 77 patients with precocious puberty. A substantial overlap was observed in basal and GnRH-stimulated gonadotropin levels in normal individuals of both sexes with pubertal Tanner stages 1 and 2. The 95th percentile of the normal prepubertal population was the cut-off limit between prepubertal and pubertal levels. These limits were 0.6 IU/L in both sexes for basal LH, 9.6 IU/L in boys and 6.9 IU/L in girls for peak LH after GnRH stimulation, 19 ng/dL in boys for basal testosterone, and 13.6 pg/mL in girls for basal estradiol. Basal and peak LH exceeding these limits were considered positive tests for the diagnosis of gonadotropin-dependent precocious puberty. According to these criteria, the sensitivities of basal and peak LH for the latter diagnosis were 71.4% and 100% in boys, and 62.7% and 92.2% in girls. The specificity and positive predicted value were 100% in both sexes for basal and peak LH levels. The negative predicted values for basal and peak LH were 62.5% and 100% in boys, and 40.6% and 76.5% in girls. Basal and GnRH-stimulated FSH levels overlapped among the various pubertal stages in normal subjects and were, in general, not helpful in the differential diagnosis of precocious puberty. In conclusion, basal LH levels were sufficient to establish the diagnosis of gonadotropin-dependent precocious puberty in 71.4% of boys and 62.7% of girls. In the remaining patients, a GnRH stimulation test was still necessary to confirm this diagnosis. Finally, suppressed LH and FSH levels after GnRH stimulation indicate gonadotropin-independent sexual steroid production.

A novel point mutation (R840S) in the androgen receptor in a Brazilian family with partial androgen insensitivity syndrome

Mutations of the androgen receptor gene causing androgen insensitivity syndrome in 46, XY individuals, result in phenotypes ranging from complete female to ambiguous genitalia to males with minor degrees of undervirilization. We studied two Brazilian brothers with partial androgen insensitivity syndrome. They were born with perineal hypospadias, bifid scrotum, small penis and cryptorchidism, and developed gynecomastia at puberty. Genomic DNA was extracted and denaturinggradient gel electrophoresis of exon 7 of the androgen receptor gene followed by sequence analysis revealed a new mutation, a C A transversion, altering codon 840 from arginine (CGT) to serine (AGT). R840 is located in the androgen binding domain, in a "hot spot" region, important for the formation and function of the hormone receptor-complex and within the region that is involved in androgen receptor dimerization. Replacement of arginine (basic) by serine (neutral and polar) is a nonconservative substitution. Three mutations in this residue (R840C, R840G nonconservative and R840H, conservative) were previously reported in patients with partial androgen insensitivity syndrome and when expressed "in vitro" lead to a subnormal transactivation of a reporter gene. We conclude that the novel R840 mutation in the androgen receptor is the cause of partial androgen insensitivity syndrome in this Brazilian family.

A novel missense mutation, GLY424SER, in Brazilian patients with 21-hydroxylase deficiency

A previous screening of 17 mutations in 130 Brazilian patients with congenital adrenal hyperplasia due to 21-hydroxylase deficiency did not identify mutations in 20% of the alleles. To diagnose these alleles we sequenced the entire CYP21 gene of one Mulatto patient with the simple virilizing form, who had only the R356W mutation in a heterozygous state. We identified a heterozygous G-A transition in codon 424. This mutation leads to a substitution of glycine by serine in a conserved region where glycine is conserved in at least 4 species. This novel mutation eliminates 1 of the restriction sites of the BanI enzyme, which made its screening possible for the whole series. The G424S mutation was found in a compound heterozygous state in 5 families; 4 presented the simple virilizing form, and 1 presented the nonclassical form. Interestingly, 3 of 5 families have a Mulatto origin. This mutation was not identified in 118 CYP21 alleles of normal individuals, ruling out the possibility of a polymorphism, or in 80 pseudogenes, indicating a casual mutagenic event and not a microconversion event. All patients with the G424S mutation presented CYP21P and C4A gene deletions and human leukocyte antigen DR17 on the same haplotype, suggesting a linkage disequilibrium and a probable founder effect. Search for the G424S mutation in other populations will reveal whether it is restricted to the Brazilian patients or if it has a wider ethnic distribution.

Insulin-like growth factor-I treatment in two children with growth hormone gene deletions

Two unrelated Brazilian patients had homozygous 6.7 kb deletions in the GH-1 gene (girl and boy, 1.8 and 3.3 yr, heights -7.9 and -6.0 SDS, respectively). Desensitization using small amounts of exogenous GH (0.033 IU/kg body weight/week, divided into daily s.c. injections) was attempted, but anti-GH antibodies appeared. Replacement with usual doses of hGH induced only transient increase in growth. IGF-I therapy with increasing doses resulted in catch-up growth without side-effects. Growth velocity was 7.5 cm/yr in the first year and 8.4 cm/yr in the next 6 months in patient 1, and 6.7 cm/yr in the first year, 5.9 cm/yr in the second year and 7.9 cm/yr in the third year of IGF-I treatment in patient 2, when the daily dose of 240 micrograms/kg was divided into three injections. IGFBP-3 levels were low (0.55 and 0.40 mg/I) and did not increase after IGF-I treatment, suggesting that this GH effect is not mediated by IGF-I, and injected IGF-I had a rapid disappearance rate. We conclude that IGF-I promotes growth by endocrine mechanisms and constitutes an effective treatment for patients with GH insensitivity secondary to GH antibodies.

Anti-corpus luteum antibody: a novel serological marker for ovarian dysfunction in systemic lupus erythematosus?

OBJECTIVE

To investigate the presence of autoantibodies directed to corpus luteum (CoL) in systemic lupus erythematosus (SLE) sera and its correlation with menstrual disturbances.

METHODS

We evaluated 87 female patients with SLE, < 40 years old, and 23 women with normal menses as controls. Anti-corpus luteum antibody was detected by immunoblot technique.

RESULTS

Reactivity to a bovine CoL antigen was found in 22% of SLE sera. Characterization of the target antigen revealed a 67 kDa glycoprotein highly enriched in corpus luteum, but nearly absent in total ovary extract. Similarly, target antigen was also weakly detectable in tissues that produce or metabolize steroids, such as testis, adrenal cortex, and liver, and it was absent in adrenal medulla or HEp-2 cells. Anti-CoL antibody was easily distinguished from other frequent reactivities of SLE sera, including anti-RNP, anti-Sm, anti-Ro/La, anti-dsDNA, or anticardiolipin. The observation of anti-67 kDa reactivity to human CoL suggests a possible pathogenic role in gonadal dysfunction. Indeed, we observed an inverse association of anti-CoL antibody with the duration of hypergonadotropic amenorrhea. Supporting this hypothesis, in patients with normal or irregular menses, the presence of this antibody was associated with elevated serum level of follicle stimulating hormone, an early and specific sign of ovarian lesion.

CONCLUSION

Anti-CoL antibody seems to be associated with early stages of ovarian dysfunction in SLE. Moreover, since similar association of antiovarian antibodies has been observed in an experimental model of autoimmune oophoritis, our findings raise the possibility of autoimmune ovarian lesion in patients with SLE.

Menstrual disorders and infertility caused by inactivating mutations of the luteinizing hormone receptor gene

OBJECTIVE

To review clinical findings, hormone levels, and DNA analyses in genetic males and females with inactivating mutations of the LH receptor gene.

DESIGN

Review of reported cases.

SETTING

A university hospital.

PATIENT(S)

Genetic males and females with inactivating mutations of the LH receptor gene.

RESULT(S)

The clinical presentation in genetic males ranged from female genitalia to male genitalia with micropenis caused by Leydig cell hypoplasia. Genetic females presented with amenorrhea or oligomenorrhea, enlarged cystic ovaries, and infertility. Both males and females had elevated LH levels and LH/FSH ratios. Sequencing of genomic DNA revealed homozygous or compound heterozygous deletions, nonsense mutations, or missense mutations in the LH receptor gene.

CONCLUSION(S)

This study of patients with inactivating mutations of the LH receptor indicates that in genetic males, the action of hCG and LH is necessary for the normal development of primary and secondary sexual characteristics. In contrast, secondary sexual characteristics develop in genetic females in the absence of LH action, but they fail to ovulate.

Treatment of gonadotropin dependent precocious puberty due to hypothalamic hamartoma with gonadotropin releasing hormone agonist depot

The gonadotropin releasing hormone (GnRH) secreting hypothalamic hamartoma (HH) is a congenital malformation consisting of a heterotopic mass of nervous tissue that contains GnRH neurosecretory neurons attached to the tuber cinereum or the floor of the third ventricle. HH is a well recognised cause of gonadotropin dependent precocious puberty (GDPP). Long term data are presented on eight children (five boys and three girls) with GDPP due to HH. Physical signs of puberty were observed before 2 years of age in all patients. At presentation with sexual precocity, the mean height standard deviation (SD) for chronological age was +1.60 (1.27) and the mean height SD for bone age was -0.92 (1.77). Neurological symptoms were absent at presentation and follow up. The hamartoma diameter ranged from 5 to 18 mm and did not change in six patients who had magnetic resonance imaging follow up. All patients were treated clinically with GnRH agonists (GnRH-a). The duration of treatment varied from 2.66 to 8.41 years. Seven of the eight children had satisfactory responses to treatment, shown by regression of pubertal signs, suppression of hormonal levels, and improvement of height SD for bone age and predicted height. One patient had a severe local reaction to GnRH-a with failure of hormonal suppression and progression of pubertal signs. It seems that HH is benign and that GnRH-a treatment provides satisfactory and safe control for most children with GDPP due to HH.

Longitudinal hormonal and pituitary imaging changes in two females with combined pituitary hormone deficiency due to deletion of A301,G302 in the PROP1 gene

Genomic DNA from 18 patients with combined pituitary hormone deficiency was screened for 2-bp deletion (A301,G302) in PROP1 gene by BcgI restriction endonuclease analysis of PCR-amplified exon 2 gene fragments. Two unrelated female patients were homozygous for this 2-bp deletion. Patient 1 presented at 8.8 yr with severe short stature (-2.9 SD score), slightly enlarged sella turcica at x-rays, and diffusely enlarged pituitary gland (height, 8 mm vs. 4.5 +/- 0.6 mm in matched controls) with hyperintense enhanced signal at T1 weighted image at coronal and sagittal views at magnetic resonance imaging (MRI). MRI repeated at age 15 yr revealed a marked reduction of pituitary height (2 mm vs. 5.3 +/- 0.8 mm in matched controls). Patient 2 presented at 27 yr with short stature (-5.5 SD score) without pubertal development, normal sella turcica, and a pituitary gland of reduced size (height, 5 mm vs. 6.1 +/- 0.3 mm in matched controls) of normal intensity at MRI. Both patients had normal pituitary stalk and normally located neurohypophysis. Hormonal features were characterized by GH, TSH, PRL, LH, and FSH deficiencies. Patient 1 had normal cortisol secretion at 8.8 yr, and at 16.6 yr had developed partial cortisol deficiency, whereas patient 2 maintained normal cortisol secretion at 28.4 yr. We conclude that 1) a large sella turcica and an enlarged pituitary anterior lobe with hyperintense enhanced signal at T1 at MRI can be suggestive of PROP1 deficiency; 2) pituitary morphology can change during follow-up of patients with PROP1 gene mutation; and 3) hormonal deficiencies could include the adrenal axis.

17Beta-hydroxysteroid dehydrogenase 3 deficiency in women

In genetic males, mutation of the 17beta-hydroxysteroid dehydrogenase 3 (17HSD3)gene that is normally expressed in the testes impairs testosterone formation and causes development of male pseudohermaphroditism. We have ascertained seven women who are sisters of men with 17HSD3 deficiency and who are either homozygotes or compound heterozygotes for the same mutations as their affected brothers. Our findings confirm the concept that women with such mutations are asymptomatic.