Developmental biology of gut-probiotic interaction

While our current knowledge of probiotic interaction in the developing gut remains poorly understood, emerging science is providing greater biological insight into their mechanism of action and therapeutic potential for human disease. Given their beneficial effects, probiotics remain promising agents in neonatal gastrointestinal disorders. Probiotics may restore or supply essential bacterial strains needed for gut maturation and homeostasis, particularly in hosts where this process has been disrupted. Here we highlight the unique characteristics of developing intestinal epithelia with a focus on gut development and colonization as well as the inflammatory propensity of immature epithelia. Additionally, we review potential mechanisms of beneficial probiotic interaction with immature intestinal epithelia including immunomodulation, upregulation of cytoprotective genes, prevention and regulation of apoptosis and maintenance of barrier function. Improved knowledge of gut-probiotic interaction in developing epithelia will allow for a better understanding of how probiotics exert their beneficial effects and help guide their therapeutic use.

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.

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.

21-Hydroxylase deficiency in Brazil

We determined the frequency of large rearrangements and point mutations in 130 Brazilian patients with 21-hydroxylase deficiency and correlated genotype with phenotype. The frequency of CYP21 deletions was lower (4.4%) than in most of the previous series described, whereas the frequency of large gene conversions was similar to the frequency reported in the literature (6.6%). The most frequent point mutations were I2 splice (41.8% in salt wasting - SW), I172N (32.6% in simple virilizing - SV) and V281L (40.2% in the late onset form - LO). The frequency of the nine most common point mutations was similar to that reported for other countries. The 93 fully genotyped patients were classified into 3 mutation groups based on the degree of enzymatic activity (A<2%, B approximately 2%, C>20%). In group A, 62% of cases presented the SW form; in group B, 96% the SV form, and in group C, 88% the LO form. We diagnosed 80% of the affected alleles after screening for large rearrangements and 15 point mutations. To diagnose these remaining alleles we sequenced the CYP21 gene of one patient with the SV form and identified a heterozygous G-->A transition in codon 424. This mutation leads to a substitution of glycine by serine in a conserved region and was also found in a compound heterozygous state in 4 other patients. The mutation G424S presented a linkage disequilibrium with CYP21P and C4A gene deletions and HLA DR17, suggesting a probable founder effect. Search for the G424S mutation in other populations will reveal if it is restricted to the Brazilian patients or if it has a wider ethnic distribution.

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.

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.

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.

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.

Low frequency of CYP2B deletions in Brazilian patients with congenital adrenal hyperplasia due to 21-hydroxylas deficiency

The frequency of large mutations was determined in 131 Brazilian patients with different clinical forms of 21-hydroxylase deficiency, belonging to 116 families. DNA samples were examined by Southern blotting hybridization with genomic CYP21 and C4cDNA probes after Taql and Bg/II restriction. Large gene conversions were found in 6.6% and CYP21B deletions in 4.4% of the alleles. The breakpoint in these hybrid genes occurred after exon 3 in 92% of the alleles. All rearrangements involving CYP21B gene occurred in the heterozygous form, except in a patient with simple virilizing form who presented homozygous CYP21B deletion. Our data showed that in these Brazilian patients, CYP21B deletions were less frequent than in most of the large series previously reported.

Molecular genotyping in Brazilian patients with the classical and nonclassical forms of 21-hydroxylase deficiency

The aim of our study was to determine, by allele-specific PCR, the frequency of point mutations in 130 Brazilian patients with the classical and nonclassical forms of 21-hydroxylase deficiency and to correlate genotype with phenotype. The most frequent mutations were 12 splice (41.8% in salt wasting), I172N (32.6% in simple virilizing), and V281L (40.2% in late onset form). The frequency of the 9 most common point mutations was similar to that reported for other countries, except for Del 8 nt and Cluster, which were less frequent in the classical form. Rarer mutations such as P453S, G291S, I7 splice, W405X, R483P, and R483-->frameshift were rarely found or were absent. The 93 fully genotyped patients were classified into 3 mutation groups, based on the degree of enzymatic activity (group A, <2%; group B, approximately 2%, and group C, >18%). In group A, 62% of the cases presented the salt wasting form; in group B, 96% the simple virilizing form; and in group C, 88% the late onset form. We diagnosed 80% of the affected alleles after screening for large rearrangements and 15 point mutations. The absence of previously described mutations in 20% of the affected alleles suggests the presence of new mutations in our population.

Serum inhibin levels before and after gonadotropin stimulation in cryptorchid boys under age 4 years

We evaluated eleven cryptorchid boys under four years of age to determine the usefulness of serum inhibin as a marker of seminiferous tubule dysfunction. Serum testosterone, inhibin, LH and FSH concentrations were measured by RIA before and after 6 weeks of human chorionic gonadotropin plus human menopausal gonadotropin therapy, and bilateral testicular biopsies were performed at orchiopexy. Hormonal results from the cryptorchid group were compared to those from an age-matched control group. Basal LH and testosterone levels were similar in the two groups. Cryptorchid boys had lower basal inhibin and higher FSH levels than controls. After gonadotropin treatment the inhibin/FSH ratio was lower in cryptorchid than control children, suggesting the presence of seminiferous tubule damage (p = 0.002). Normal numbers of spermatogonia were seen in 6/9 scrotal and in 1/13 cryptorchid testes. The peak of inhibin was positively correlated to the number of spermatogonia (r = 0.68; p = 0.02). We conclude that basal and stimulated inhibin concentrations, as well as basal and stimulated inhibin/FSH ratio, provide additional information on seminiferous tubule function in cryptorchid boys and can be useful to evaluate Sertoli cell function in these patients.

The PROP1 2-base pair deletion is a common cause of combined pituitary hormone deficiency

Combined pituitary hormone deficiency (CPHD) has an incidence of approximately 1 in 8000 births. Although the proportion of familial CPHD cases is unknown, about 10% have an affected first degree relative. We have recently reported three mutations in the PROP1 gene that cause CPHD in human subjects. We report here the frequency of one of these mutations, a 301-302delAG deletion in exon 2 of PROP1, in 10 independently ascertained CPHD kindreds and 21 sporadic cases of CPHD from 8 different countries. Our results show that 55% (11 of 20) of PROP1 alleles have the 301-302delAG deletion in familial CPHD cases. Interestingly, although only 12% (5 of 42) of the PROP1 alleles of our 21 sporadic cases were 301-302delAG, the frequency of this allele (in 20 of 21 of the sporadic subjects given TRH stimulation tests) was 50% (3 of 6) and 0% (0 of 34) in the CPHD cases with pituitary and hypothalamic defects, respectively. Using whole genome radiation hybrid analysis, we localized the PROP1 gene to the distal end of chromosome 5q and identified a tightly linked polymorphic marker, D5S408, which can be used in segregation studies. Analysis of this marker in affected subjects with the 301-302delAG deletion suggests that rather than being inherited from a common founder, the 301-302delAG may be a recurring mutation.

Clinical and molecular characterization of a Brazilian patient with Pit-1 deficiency

We studied a 14 year-old girl with extreme short stature (-9.5 SDS), normal psychomotor development and signs of progressive hypothyroidism. Basal IGF-I and T4 were low. Serum GH was low after insulin-induced hypoglycemia and GH-releasing hormone administration. Both TSH and prolactin were low and did not rise after TRH administration. Gonadotropins were normal and cortisol levels were elevated. In contrast, DHEA-S levels were low and she did not develop pubic hair until 26 years of age, compatible with deficiency of a putative pituitary adrenal androgen stimulating hormone. Pituitary size was reduced on magnetic resonance imaging. Sequencing of the Pit-1 gene revealed a heterozygous C to T transition in codon 271 resulting in substitution of tryptophane for a highly conserved arginine. Her parents were homozygous normal for this locus indicating a de novo mutation with dominant expression. Genetic and phenotypic heterogeneity of patients with Pit-1 gene mutations, particularly the R271W mutation, may reveal further information about the nature of genetic silencing, imprinting, and epigenetic inheritance. The relationship of Pit-1 deficiency to abnormal adrenal secretion remains to be elucidated.

A unique constitutively activating mutation in third transmembrane helix of luteinizing hormone receptor causes sporadic male gonadotropin-independent precocious puberty

Several constitutively activating mutations have been demonstrated in the sixth transmembrane helix of the human LH receptor (hLHR) in boys with gonadotropin-independent precocious puberty. In the current study, we examined two unrelated Brazilian boys with gonadotropin-independent precocious puberty caused by two different heterozygous activating mutations of the hLHR. Direct sequencing of the entire exon 11 of the hLHR revealed a heterozygous substitution of T for G at nucleotide 1370, that converts Leu 457 to Arg in the third transmembrane helix of the hLHR in one affected boy. His biological parents had a normal hLHR gene sequence, establishing the sporadic nature of this novel Leu457Arg mutation. Human embryonic 293 cells expressing hLHR mutant (L457R) or hLHR wild-type bound CG with high affinity. However, cells expressing hLHR(L457R) exhibited significantly higher basal levels of cAMP (7- to 14-fold) than cells expressing the wild-type receptor, indicating constitutive activation of hLHR(L457R). Basal levels of cAMP in hLHR(L457R)-expressing cells were, nonetheless, not as great as the levels of cAMP produced by hLHR wild-type-expressing cells incubated with a saturating concentration of CG. Furthermore, cells expressing hLHR(L457R) were unresponsive to further stimulation by CG. This finding was confirmed in the patient by lack of an increase in serum testosterone after CG stimulation. These results suggest that the conformation of hLHR(L457R) mutant represents a different activated receptor state (R*) than the agonist-occupied wild-type receptor. We also identified the previously described Ala568Val mutation in the third intracellular loop of the LHR in the other affected African-Brazilian boy and his normal prepubertal sister, suggesting the inherited form of precocious puberty in this boy. We conclude that the third transmembrane helix is a potential area for activating mutations of the hLHR that cause male precocious puberty.

Clinical and molecular characterization of Brazilian patients with growth hormone gene deletions

Genomic DNA from 23 patients with isolated growth hormone (GH) deficiency (12 males and 11 females: heights -4.9 +/- 1.4 SDS) was screened for GH gene deletions by restriction endonuclease analysis of polymerase chain reaction amplification products. Three unrelated patients had typical features of severe GH deficiency and deletions (6.7 kb in two and 7.6 kb in one) of the GH gene. The two patients with 6.7-kb deletions developed growth-attenuating anti-GH antibodies whereas the patient with the 7.6-kb deletion continued to grow with GH replacement therapy. Our finding that 3/23 (approximately 13%) Brazilian subjects had GH gene deletions agrees with previous studies of severe isolated GH deficiency subjects in other populations. Two of three subjects (67%) with deletions developed blocking antibodies despite administration of exogenous GH at low doses. Interestingly, only 1/10 of cases with affected relatives or parental consanguinity had GH-1 gene deletions.

A homozygous microdeletion in helix 7 of the luteinizing hormone receptor associated with familial testicular and ovarian resistance is due to both decreased cell surface expression and impaired effector activation by the cell surface receptor

In this report, the genomic DNA was examined from two siblings with gonadal LH resistance. A 46,XY pseudohermaphrodite presented with female external genitalia and his 46,XX sister exhibited menstrual irregularities (oligoamenorrhea) and infertility. Exons 1-11 of the LH receptor (LHR) gene were amplified by the PCR using different sets of intronic primers and were directly sequenced. Sequencing revealed that both individuals carried a deletion of nucleotides 1822-1827, resulting in the deletion of Leu-608 and Val-609 within the seventh transmembrane helix. This mutation was introduced into a recombinant human (h) LHR cDNA. Transfections of 293 cells with hLHR(wt) vs. hLHR(deltaL608,V609) revealed that very little of the mutant receptor was expressed at the cell surface. This was due to both a decrease in the total amount of receptor expressed as well as to an increased intracellular retention of the mutant receptor. In spite of the decreased cell surface expression of the mutant, sufficient amounts were present to allow for assessment of its functions. Equilibrium binding assays showed that the cell surface hLHR(deltaL608,V609) binds hCG with an affinity comparable to that of the wild-type receptor. However, the cells expressing the hLHR(deltaL608,V609) exhibit only a 1.5- to 2.4-fold stimulation of cAMP production in response to hCG. In contrast, cells expressing comparably low levels of hLHR(wt) responded to hCG with 11- to 30-fold increases of cAMP levels. Therefore, the testicular and ovarian unresponsiveness to LH in these patients appears to be due to a mutation of the hLHR gene in which Leu-608 and Val-609 are deleted. As a consequence, the majority of the mutant receptor is retained intracellularly. The small percentage of mutant receptor that is expressed at the cell surface binds hormone normally but is unable to activate Gs.

Apparent mineralocorticoid excess in a Brazilian kindred: hypertension in the heterozygote state

BACKGROUND

Apparent mineralocorticoid excess (AME) is a cause of low-renin, low-aldosterone hypertension in which cortisol acts as a mineralocorticoid. The condition reflects an inability to inactivate cortisol to cortisone due to defective activity of the type 2 isozyme of 11beta-hydroxysteroid dehydrogenase (11beta-HSD2). Homozygous mutations in 11beta-HSD2 gene in patients with AME have been described. A 7-year-old Brazilian girl had previously been found to have AME. Her father recently presented with mineralocorticoid hypertension at age 38 years.

OBJECTIVE

To describe the clinical details, to perform steroid analyses and to assess the molecular basis for the hypertension in this kindred.

METHODS

The 11beta-HSD2 gene was amplified from genomic DNA by the polymerase chain reaction and sequenced by direct chain-termination sequencing on an automatic DNA sequencer. The sequencing results were validated by restriction-site polymorphism. The mutant 11beta-HSD2 protein was expressed in Chinese hamster ovary polyoma cells and enzymatic activity was assessed by metabolizing cortisol in vitro.

RESULTS

Sequence analysis of genomic DNA revealed a novel C1061T point mutation in exon V of the human 11beta-HSD2 gene, resulting in an amino acid substitution of alanine by valine at codon 328 of the enzyme protein (A328V). Expression studies confirmed that the mutant protein was devoid of 11beta-HSD2 activity. A HhaI restriction-site polymorphism confirmed that the proband was homozygous for the mutation whereas both parents were heterozygotes. The father of the proband had hypertension, a normal serum potassium level, suppressed plasma renin activity and plasma aldosterone level and a moderately elevated urinary cortisol: cortisone metabolite ratio.

CONCLUSIONS

AME in this kindred is caused by a novel mutation in the 11beta-HSD2 gene. Detection of hypokalaemia, at least in this kindred, is an insensitive screening test for mineralocorticoid-based hypertension. In contrast to results from previously investigated kindreds, we have demonstrated that this kindred has an abnormal phenotype in the heterozygote state. Further studies are now required in order to evaluate the role of 11beta-HSD2 activity in the pathophysiology of 'essential' hypertension.

Long-acting gonadotropin-releasing hormone agonists in the differential diagnosis of male precocious puberty

Male sexual precocity is defined as the development of secondary sexual characteristics before 9 years of age. It can be classified as gonadotropin-dependent precocious puberty (GnDP) or gonadotropin-independent precocious puberty (GnIP) and sometimes the differential diagnosis between these entities is difficult. To determine whether long-acting GnRH agonists (GnRH-a) are effective in differential diagnosis of male precocious puberty, we measured gonadotropins and testosterone levels 30 days after a single administration of depot GnRH-a (triptorelin, gosereline or leuprolide) in 10 boys with sexual precocity of different etiologies. Testosterone levels 30 days after depot GnRH-a were in the prepubertal range in patients with GnDP but not in GnIP. We conclude that measurement of testosterone levels 30 days after long-acting GnRH-a is effective in the differential diagnosis of male sexual precocity.

Ovarian resistance to luteinizing hormone: a novel cause of amenorrhea and infertility

OBJECTIVE

To report the clinical, hormonal, and histopathological features of a woman with ovarian resistance to LH.

DESIGN

Clinical study.

SETTING

University hospital.

PATIENT(S)

A woman with amenorrhea, sister of a patient with male pseudohermaphroditism due to Leydig cell hypoplasia.

INTERVENTION(S)

Blood drawing before and after GnRH stimulation and also after dexamethasone and hCG administration, pelvic ultrasound, and ovarian biopsy.

MAIN OUTCOME MEASURE(S)

Karyotype, gonadotropin and steroid measurements, follicular diameter, ovarian histology, and sequencing of the LH receptor gene.

RESULT(S)

Patient had normal female external genitalia, normal breast development at puberty, rare episodes of vaginal bleeding, and infertility. The karyotype was 46,XX. She had elevated serum LH levels, whereas E2 and P concentrations were in the range seen in the early follicular phase. Pelvic ultrasound revealed a slightly hypoplastic uterus and enlarged polycystic ovaries. A normal follicular reserve for age, antral follicles, and absence of corpora lutea or albicans were observed on ovarian biopsy. Exon 11 of the LH receptor gene had a normal sequence.

CONCLUSION(S)

In our patient with ovarian resistance to LH, FSH stimulated follicular development until the preovulatory stage, but E2 levels remained in the early follicular phase range, still sufficient for normal pubertal feminization. Apparently, LH is necessary for ovulation and corpus luteum formation.

Management of ambiguous genitalia in pseudohermaphrodites: new perspectives on vaginal dilation

OBJECTIVE

To evaluate vaginal size and sexual activity after different techniques of feminization of external genitalia in patients with pseudohermaphroditism.

DESIGN

Retrospective clinical study.

SETTING

Pseudohermaphrodite patients seen at our institution.

PATIENT(S)

Three female and 20 male pseudohermaphrodites raised as females.

INTERVENTION(S)

Bilateral orchidectomy, feminization of external genitalia (clitoridectomy or clitoroplasty, urogenital sinus enlargement), and/or neovaginoplasty or vaginal dilation with acrylic molds.

MAIN OUTCOME MEASURE(S)

Psychological evaluation, vaginal size, and quality of intercourse.

RESULT(S)

All patients referred sexual drive to men. Fifty percent of the patients who were submitted to neovaginoplasty referred pain or bleeding during sexual intercourse. On the other hand, 87% of the patients who were submitted to vaginal dilation with acrylic molds, after genitoplasty or not, referred satisfactory sexual intercourse. All patients who were submitted to clitoroplasty referred orgasm and 29% of the patients submitted to clitoridectomy referred no orgasm. Of three patients with congenital adrenal hyperplasia due to 21-hydroxylase deficiency, two became pregnant and delivered normal children through cesarian section.

CONCLUSION(S)

In pseudohermaphrodites with female social sex, surgical correction of external genitalia performed in childhood and vaginal dilation with acrylic molds performed when they wished to start having sexual intercourse resulted in best outcome.

Male pseudohermaphroditism due to steroid 5alpha-reductase 2 deficiency. Diagnosis, psychological evaluation, and management

Sixteen subjects (from 10 Brazilian families) with male pseudohermaphroditism due to steroid 5alpha-reductase 2 deficiency have been evaluated in 1 clinic. The diagnoses were made on the basis of normal plasma testosterone values, normal or low plasma dihydrotestosterone levels and high testosterone/dihydrotestosterone ratios in the basal state in postpubertal subjects or after treatment with either human chorionic gonadotropin or testosterone in prepubertal subjects. The analysis of the ratios of etiocholanolone to androsterone in urine confirmed the diagnosis in all subjects who were tested, and the molecular basis of the underlying mutations was established in 9 of the families. Fourteen of the individuals were evaluated by the same psychologist. All subjects but 1 were given a female sex assignment at birth. Three of the subjects (1 the sibling of an individual who has undergone female to male social behavior) maintain a female social sex; they have been gonadectomized and treated with exogenous estrogens. Ten of 13 subjects of postpubertal age underwent a change of social sex from female to male, had surgical correction of the hypospadias, and were treated with high-dose testosterone esters by parenteral injection and subsequently with dihydrotestosterone cream. These regimens brought serum dihydrotestosterone levels to the normal male range (or above) but resulted only in limited growth of the prostate and penis and, in some, increase in body and facial hair and enhancement of libido and sexual performance. Treatment of the prepubertal boys with testosterone and/or dihydrotestosterone resulted in a doubling of penis size.

A novel mutation of the luteinizing hormone receptor gene causing male gonadotropin-independent precocious puberty

Familial male-limited precocious puberty (FMPP) is an autosomal dominant gonadotropin-independent disorder. Affected males generally develop signs of precocious puberty in early childhood. They typically show Leydig cell hyperplasia and increased testosterone production typical for their age, whereas circulating LH concentrations remain prepubertal. Several dominant point mutations of the LH receptor gene were identified in pedigrees with familial male-limited precocious puberty and were shown to cosegregate with the disease. Here we report a novel heterozygote point mutation in the LH receptor gene of a Brazilian boy with gonadotropin-independent precocious puberty. This mutation substitutes alanine 568 with valine at the carboxyterminus of the third cytosolic loop of the LH receptor. The unoccupied mutant receptors confer constitutive activation of adenyl cyclase activity when expressed in COS-7 cells, resulting in 4-fold higher cAMP concentrations over baseline compared with cells expressing an equivalent number of wild-type receptors. The affinity of the mutant receptors to 125I-labeled human LH was not altered compared with the wild type. Mutations of the homologue alanine residue in the alpha 1-adrenergic (in vitro), FSH (in vitro), and TSH (naturally occurring) receptors also result in constitutive adenyl cyclase activation, suggesting that this alanine residue is crucial for signal transduction and a potential site for upregulatory/oncogenic mutations in G-protein coupled receptors.

Human androgen insensitivity due to point mutations encoding amino acid substitutions in the androgen receptor steroid-binding domain

Mutations of the human androgen receptor gene were identified in five subjects from four families with androgen insensitivity syndrome. Individual exons of the androgen receptor gene were amplified by the polymerase chain reaction from genomic DNA and screened for sequence-dependent differences in their melting characteristics by denaturing gradient gel electrophoresis. DNA fragments from exons with altered mobility were sequenced. Four different single nucleotide base substitutions were found within exons 5, 6, and 7 encoding the steroid-binding domain of the androgen receptor. In one subject with ambiguous genitalia, amino acid residue 763 was changed from tyrosine to cysteine (TAC-->TGC; Y763C). Four subjects, including two siblings, had complete androgen insensitivity. In one subject, residue 779 was changed from arginine to tryptophan (CGC-->TGG; R779W), another subject (M807V) had a substitution of valine (GTG) for methionine (ATG) residue at position 807, and the two siblings (R855C) had a mutation in residue 855 changing arginine (CGC) to cysteine (TGC). Binding of the synthetic androgen ligand, methyltrienolone (R1881), by the mutant receptor Y763C was decreased by 54% compared to the normal receptor. Transcriptional activation of a mouse mammary tumor virus-chloramphenicol acetyltransferase (MMTV-CAT) reporter gene by AR mutant Y763C was negligible at 0.1 nM R1881 and only 55% at 10 nM R1881 when compared to the maximal response with the normal AR, as assessed by CAT activity. Mutant M807V retained only 22% of normal R1881 binding and mutant R855C was unable to bind the steroid. In accordance with the steroid binding, transcriptional activation of MMTV-CAT by M807V rose to only 26% of control in the presence of 10 nM R1881, a concentration at which R855C remained functionally inactive. In summary, missense mutations within the exons of the androgen receptor gene encoding the steroid-binding domain of the receptor are common causes of both partial and complete forms of androgen insensitivity syndrome.

Gonadal agenesis in XX and XY sisters: evidence for the involvement of an autosomal gene

Two agonadic sisters, one with a 46,XY and the other with a 46,XX karyotype, both with normal female external genitalia and hypoplastic Müllerian derivatives, born to a consanguineous marriage, were studied from a clinical, endocrinological, histological, and genetic perspective. Using PCR amplification, Southern hybridization, and DGGE analysis, it was found that the XY patient had no mutations in the conserved sequence of the SRY gene, the putative testis-determining gene in mammals, whereas her XX affected sister is SRY-negative. To our knowledge, this is the first report of XY and XX sibs in familial gonadal agenesis without other somatic abnormalities. The involvement of an autosomal locus impeding gonadal development in both sexes is discussed.

Mutation in 3 beta-hydroxysteroid dehydrogenase type II associated with pseudohermaphroditism in males and premature pubarche or cryptic expression in females

A mutation (A82T) is described in the coding sequence of the gene for 3 beta-hydroxysteroid dehydrogenase (3 beta-HSD) type II that is associated with variable clinical consequences. Four homozygotes are described, all of which showed elevated levels of delta 5 steroids consistent with 3 beta-HSD deficiency. Two males from a consanguineous family were found to be homozygous for A82T and were affected with pseudohermaphroditism. They differed in their degree of mild salt loss. In the same family a female was found to be homozygous for A82T, but was clinically normal and had no history of premature pubarche or of abnormal menstrual cycles. However, in an apparently unrelated family, the A82T mutation was found in a female affected with premature pubarche. This is the first report of a proven mutation in 3 beta-HSD type II associated with premature pubarche.

Sleep characteristics of adolescents: a longitudinal study

The aim of the present research was to study sleep/wake cycle parameters of adolescents and to examine biologic and social influences on their changing sleep patterns. This was a longitudinal study of sleep characteristics of a group of 66 adolescents (mean age, 13 years and 6 months). The adolescents underwent a physical examination, had their pubertal development classified according to Tanner stages, and answered a sleep questionnaire on three timepoints at 6-month intervals. Sleep onset occurred about 1.0 hr later, wake-up time about 3.0 hr later, and sleep length was 1.0-1.5 hr longer on weekends when compared with weekdays. About 60% of the adolescents reported daytime sleepiness, mainly from 8:00 a.m. to 10:00 a.m. and from 2:00 p.m. to 4:00 p.m. on school days. Morning sleepiness on school days occurred at a time of the day that corresponded to sleep on non-school days. Additionally, there was a displacement toward later hours of the wake-up time and a sleep-length increase during weekends from the first to the third timepoint. Social factors such as home conditions and scheduling of school and non-school activities did not change throughout the period of pubertal development studied. Changes of sleep patterns detected may therefore represent an ontogenetic trend along puberty.

Identification of nonclassical 21-hydroxylase deficiency in girls with precocious pubarche

Recent studies have described mild adrenal enzymatic defects in patients presenting with precocious pubarche. In order to identify these defects we have evaluated basal and ACTH- (25 IU iv) stimulated serum adrenal steroid levels in 19 girls, 2- to 8.3-year-old, with precocius pubarche (pubic hair Tanner II-III). Two patients had clitorial enlargement. Bone age was moderatly advanced in 10 patients and 2 to 3.7 yr in four others. Four patients had high basal serum levels of 17-hydroxyprogesterone (17OHP) (525 + 202 ng/dl, mean +SD), compatible with the diagnosis of nonclassical congenital adrenal hyperplasia due to 21-hydroxylase deficiency (NCCAH-21OH), which was confirmed by an increased response of 17OHP to ACTH (3425 +/- 953 ng/dl). Fifteen patients had moderately elevated basal 17OHP levels (56 + 38 ng/dl) but a normal 170HP response (191 +/- 71 ng/dl) to ACTH, compatible with the diagnosis of idiopathic precocious pubarche (IPP). The cortisol response to ACTH was normal in both groups. Basal values of DHEA-S were 651 +/- 256 and 506 + 462 ng/ml and of DHEA 380 +/- 24 ng/dl and 205 +/- 102 ng/dl, in NCCAH-210H and IPP, respectively. We conclude that: i) clinical findings and baseline levels of DHEA-S and DHEA in IPP can be indistinguishable from the late onset 21 hydroxylase deficiency; ii) baseline levels of 17OHP are sufficient for the diagnosis of NCCAH-21OH; iii) the ACTH stimulation test is indicated only when baseline levels of 17OHP are moderately elevated (100-300 ng/dl).

Normal expression of the serologically defined H-Y antigen in Leydig cell hypoplasia

H-Y antigen, the proposed inducer of testicular organogenesis, was determined serologically in 3 patients with male pseudohermaphroditism due to Leydig cell hypoplasia, a pathological model with lack of Leydig cell differentiation but normal seminiferous tubule embryogenesis. One patient was the offspring of consanguineous parents and 2 siblings presented as women with a lack of breast development and primary amenorrhea. Gonads were palpable in the inguinal canal, except for the right intra-abdominal testis in 1 patient. Two patients had female external genitalia and 1 had partial labial fusion. Karyotypes were 46XY. Gonadotropin levels were elevated, and testosterone was low and failed to increase after stimulation with human chorionic gonadotropin. Testosterone precursors were not elevated. Testicular histology showed absence of mature Leydig cells but relatively preserved seminiferous tubules. Family history was consistent for autosomal recessive inheritance. H-Y antigen expression measured by an enzyme-linked immunosorbent assay was normal, indicating that lack of other inductive factors for Leydig cell differentiation are responsible for Leydig cell hypoplasia.

Prepubertal male pseudohermaphroditism due to 17-ketosteroid reductase deficiency: diagnostic value of a hCG test and lack of HLA association

Most patients with male pseudohermaphroditism (MPH) due to 17-ketosteroid reductase (17-KSR) deficiency were diagnosed at or after puberty when significant virilization occurred. We report 2 prepubertal sibs (Case 1, 4 yr and Case 2, 10 yr) unambiguously raised as females, with clitoral enlargement, separate urethral and vaginal orifices and gonads palpable at the inguinal canal bilaterally. Basal serum LH, FSH, 17-hydroxyprogesterone, testosterone (T), dihydrotestosterone and dehydroepiandrosterone (DHEA) were normal for age. delta 4-Androstenedione (delta 4-A) was slightly elevated in Case 2 but nondiagnostic. Steroid measurements after human chorionic gonadotropin (hCG) stimulation were compared with those of boys with male external genitalia submitted to the same hCG protocol: peak T was subnormal (Case 1, 80, Case 2, 91, vs normal 329 +/- 129 ng/dl, mean +/- 1SD), peak delta 4-A elevated (Case 1, 477, Case 2, 264, vs normal 44 +/- 26 ng/dl) resulting in an abnormally elevated delta 4-A/T ratio (Case 1, 6.0, Case 2, 2.9, vs normal 0.12 +/- 0.09) and establishing the diagnosis of 17-KSR deficiency. This diagnosis was confirmed in vitro by minimal T production when testicular tissue of both patients was incubated with tritiated delta 4-A. The 2 sibs did not share a single haplotype for the HLA complex indicating lack of association between HLA and the locus of the gene for 17-KSR. In conclusion, in 2 sibs with MPH the subnormal T and elevated delta 4-A response to the hCG test indicated the diagnosis of 17-KSR deficiency followed by orchiectomy to avoid later virilization at puberty.

Male pseudohermaphroditism due to nonsalt-losing 3 beta-hydroxysteroid dehydrogenase deficiency: gender role change and absence of gynecomastia at puberty

Adrenal and gonadal functions were evaluated on two adult cousins with male pseudohermaphroditism due to congenital 3 beta-hydroxysteroid dehydrogenase deficiency (3 beta-HSD) without clinical salt-losing. Both patients had been reared as females since birth. Case 1 presented at age 17 with perineal hypospadias virilization without gynecomastia and a female to male gender role change at puberty. Case 2 had previously undergone bilateral orchidectomy in childhood and presented "primary amenorrhea", absence of virilization and a female gender role at the age of 24. In the basal state, as well as after ACTH and hCG stimulation, 3 beta-hydroxy-5-ene-steroid levels were disproportionately elevated, resulting in abnormal 3 beta-hydroxy-5-ene: 3-oxi-4-ene steroids ratios. Normal basal serum cortisol with inadequate cortisol response to ACTH was observed in both patients. Elevated basal plasma renin activity (PRA) and normal basal serum aldosterone (ALDO) were present in both subjects. After ACTH stimulation serum ALDO rose adequately in Case 1 but subnormally in Case 2. Salt restriction resulted in an increase in serum ALDO and no salt loss in Case 1 whereas in Case 2 the substantial rise in PRA and serum ALDO were unable to prevent slight urinary sodium loss. Case 1 had normal basal serum testosterone with subnormal response to hCG stimulation. Incubation of testicular tissue in vitro with [3H]DHEA resulted in large Androstenediol production but diminished testosterone conversion confirming the 3 beta-HSD deficiency in the testes. We conclude that (1) absence of gynecomastia and a female to male gender role change may be observed in the male pubertal presentation of nonsalt-losing 3 beta-HSD deficiency and (2) the different functional behavior of zona glomerulosa in our patients suggests the presence of variable degrees of 3 beta-HSD deficiency in the zona glomerulosa of the nonsalt-losing form.