Relative Frequency of Islet Autoimmunity in Children and Adolescents with Autoimmune Thyroid Disease

Objective

The aim of the present study was to investigate islet autoimmunity and susceptibility to type 1 diabetes (T1D) in children/adolescents with autoimmune thyroid disease (AITD, and in family members of AITD patients with islet autoimmunity.

Methods

Islet-cell cytoplasmic, glutamic-acid decarboxylase, and tyrosine-phosphatase autoantibodies (AAbs) were measured in 161 AITD patients [127 with autoimmune thyroiditis (AT); 34 with Graves’ disease (GD)], 20 family members of AITD patients with islet autoimmunity, and 155 age-matched controls.

Results

Islet autoimmunity was found in 10.6% of AITD patients, significantly more frequent than in controls (1.9%; p=0.002). A higher prevalence of islet AAbs was found in females with AITD (p=0.011) but not in males (p=0.16) and in AT (p=0.013) but not in GD patients (p=0.19), compared to corresponding controls. Two or three islet AAbs were found concurrently in six AITD patients with islet autoimmunity. They all developed T1D and had significantly higher islet AAbs titers (p=0.01) than AITD patients with single islet AAbs but normal glucose metabolism. T1D was found in 3.7% of AITD patients compared to 0.2% of the age-matched, general Croatian population. Islet AAbs were found in 5/20 family members of AITD patients with islet autoimmunity, among whom two developed T1D. None of the controls was positive for more than one islet AAb or developed T1D.

Conclusion

Children/adolescents with AITD, particularly females and patients with AT, appear to represent a risk group for islet autoimmunity and T1D, as do family members of AITD patients with positive islet AAbs. However, these findings should be validated in larger studies.

The prevalence and genotype of 21-hydroxylase deficiency in the Croatian Romani population

Objective

Congenital adrenal hyperplasia (CAH) owing to 21-hydroxylase deficiency (21-OHD) is a rare autosomal recessive disorder caused by pathological variants in the CYP21A2 gene. After a high prevalence of classic 21-OHD CAH in the Romani population was reported in the Republic of North Macedonia, we decided to estimate the prevalence of 21-OHD in Croatia and, if high, assess the possible causes and estimate the frequency of particular CYP21A2 variants.

Design

Cross-sectional study.

Methods

Data from a Croatian 21-OHD genetic database was reviewed, and only Romani patients were included in the study. CYP21A2 genotyping was performed using allele-specific PCR, MLPA, and Sanger sequencing.

Results

According to a survey conducted in 2017, Croatia had 22,500 Romani people and six of them had a salt-wasting (SW) form of 21-OHD. All were homozygous for the c.IVS2-13A/C-G pathological variant in intron 2 and descended from consanguineous families belonging to different Romani tribes. The calculated prevalence of 21-OHD in Croatian Romani is 1:3,750, while in the Croatian general population, it is 1:18,000. Three of the six Romani patients originated from two neighboring villages in North-western Croatia (Slavonia County), as well as the seventh patient who is of mixed Romani/Croatian descent and heterozygous for the c.IVS2-13A/C-G pathological variant (not included in the prevalence calculation).

Conclusion

A high prevalence of SW 21-OHD in the Croatian Romani population caused by the homozygous cIVS2-13A/C-G pathological variant was found. In addition to isolation and consanguinity, other possible reasons could be the heterozygous advantage of the CYP21A2 gene pathological variant and the bottleneck effect as a result of the Romani Holocaust in World War II.

Two Single Nucleotide Deletions in the ABCD1 Gene Causing Distinct Phenotypes of X-Linked Adrenoleukodystrophy

X-linked adrenoleukodystrophy (X-ALD) is a rare inborn error of the peroxisomal metabolism caused by pathologic variants in the ATP-binding cassette transporter type D, member 1 (ABCD1) gene located on the X-chromosome. ABCD1 protein, also known as adrenoleukodystrophy protein, is responsible for transport of the very long chain fatty acids (VLCFA) from cytoplasm into the peroxisomes. Therefore, altered function or lack of the ABCD1 protein leads to accumulation of VLCFA in various tissues and blood plasma leading to either rapidly progressive leukodystrophy (cerebral ALD), progressive adrenomyeloneuropathy (AMN), or isolated primary adrenal insufficiency (Addison's disease). We report two distinct single nucleotide deletions in the ABCD1 gene, c.253delC [p.Arg85Glyfs*18] in exon 1, leading to both cerebral ALD and to AMN phenotype in one family, and c.1275delA [p.Phe426Leufs*15] in exon 4, leading to AMN and primary adrenal insufficiency in a second family. For the latter variant, we demonstrate reduced mRNA expression and a complete absence of the ABCD1 protein in PBMC. Distinct mRNA and protein expression in the index patient and heterozygous carriers does not associate with VLCFA concentration in plasma, which is in line with the absence of genotype-phenotype correlation in X-ALD.

Testicular adrenal rest tumors in congenital adrenal hyperplasia-cross-sectional study of 51 Croatian male patients

Testicular adrenal rest tumors (TARTs) are common cause of infertility in males with congenital adrenal hyperplasia (CAH). We studied the role of genotype and disease regulation on TART development, their impact on gonadal function, and frequency in 47 21-hydroxylase deficiency (21-OHD) and four 11-hydroxylase deficiency (11-OHD) male patients. Testicular ultrasound (TU), genotype, hormonal measurement in 51, and spermiogram in five patients were performed. TARTs were detected in 14 SW21-OHD and one 11-OHD patient: 1/8 patients aged <7 years (1.8 years old is the youngest), 1/8 patients aged <12 years, 5/17 patients aged <18 years, and in 8/18 adults. All 21-OHD TART patients had exclusively severe mutations of CYP21A2 gene. Poor hormonal control in 8/15 patients with and 12/36 patients without TART indicates correlation of tumor development with poor disease control. None of the TART patients fathered a child. Low inhibin-B was found in 7/15 TART patients. Azoospermia was found in four and oligoasthenozoospermia in one patient.

CONCLUSION

TART was detected exclusively in patients with severe CYP21A2 mutations. Disease regulation plays a role in development of TART that impairs testicular function and increases the risk of infertility. Screening for TART by TU is indicated from early childhood. What is Known: • Due to improved diagnostic and therapeutic possibilities, majority of the male patients with congenital adrenal hyperplasia nowadays reach adulthood and screening for long-term complications is becoming more important. • Testicular adrenal rest tumors (TARTs) are common cause of infertility and impaired gonadal function in males with CAH. What is New: • A 1.8-year-old boy described in this paper is the youngest reported patient with TART. • Screening for TART by testicular ultrasound from early childhood, especially in patients with severe CYP21A mutations, is recommended.

Clinical, genetic, and structural basis of congenital adrenal hyperplasia due to 11β-hydroxylase deficiency

Congenital adrenal hyperplasia (CAH), resulting from mutations in CYP11B1, a gene encoding 11β-hydroxylase, represents a rare autosomal recessive Mendelian disorder of aberrant sex steroid production. Unlike CAH caused by 21-hydroxylase deficiency, the disease is far more common in the Middle East and North Africa, where consanguinity is common often resulting in identical mutations. Clinically, affected female newborns are profoundly virilized (Prader score of 4/5), and both genders display significantly advanced bone ages and are oftentimes hypertensive. We find that 11-deoxycortisol, not frequently measured, is the most robust biochemical marker for diagnosing 11β-hydroxylase deficiency. Finally, computational modeling of 25 missense mutations of CYP11B1 revealed that specific modifications in the heme-binding (R374W and R448C) or substrate-binding (W116C) site of 11β-hydroxylase, or alterations in its stability (L299P and G267S), may predict severe disease. Thus, we report clinical, genetic, hormonal, and structural effects of CYP11B1 gene mutations in the largest international cohort of 108 patients with steroid 11β-hydroxylase deficiency CAH.

Molecular genetic analysis in 93 patients and 193 family members with classical congenital adrenal hyperplasia due to 21-hydroxylase deficiency in Croatia

Congenital adrenal hyperplasia owing to 21-hydroxylase deficiency is caused by mutation in the CYP21A2 gene. The frequency and spectrum of CYP21A2 mutations and genotype-phenotype correlations among different populations are variable. Aim of this study was to define mutation frequency and spectrum of CYP21A2 gene mutations in patients with classical 21-hydroxylase deficiency (21OHD) and their family members in Croatia and study genotype-phenotype correlation. Clinical features and mutations of CYP21A2 gene in 93 unrelated 21OHD patients and 193 family members were examined. In this cohort, 66 patients were affected with salt wasting (SW) form, and 27 were affected with simple virilizing (SV) form of the disease. Mutations were identified in both alleles (67% compound heterozygous and 33% homozygous) in 91 of 93 patients. Deletions and conversions were found in 18.8% and point mutations in 79.6% alleles. Mutations in 3 alleles (1.6%) remained unidentified (in one patient we found only one, while in other no mutations were found at all). The most common point mutations were Intron 2 splice mutation IVS2-13 A/C>G (35.5%) and p.R357W (16.7%). Genotypes were categorized into Groups 0, A, B and C according to the extent of enzyme impairment. Genotype-phenotype concordance was 100%, 85% and 75% for Groups 0, A and B, respectively. Since only classical 21OHD patients were studied, Group C comprised solely p.P31L mutation and had 73% patients with SV and 27% with SW phenotype. Intrafamilial phenotypic variability was found in two families. CYP21A2 genetic analysis in 193 family members showed that 126 parents were heterozygous carriers, 3 were newly discovered patients, 2 fathers were not biological parents, and mutations were not detected in 3. Among 59 siblings, 32 were heterozygous carriers, 15 carried normal alleles, and 12 were patients (4 newly diagnosed). Genotype-phenotype divergence observed in this study suggests caution in preconceptional counseling and prenatal diagnosis of CAH. High frequency of p.R357W mutation was found in Croatian patients with classical 21-OHD. Genotyping of family members discovered new patients and thus avoided pitfalls in genetic counseling when the parents were found to be affected.

Association of HLA alleles and haplotypes with CYP21A2 gene p. V282L mutation in the Croatian population

The CYP21A2 mutations that are in linkage disequilibrium with particular HLA-A, -B, -DRB1 alleles/haplotypes, cause deficiency of the 21-hydroxylase enzyme (21-OHD) and account for the majority of congenital adrenal hyperplasia (CAH) cases. The aim of this study was to investigate those associations with the p.V282L mutation linked to the non-classical (NC) form of CAH among Croatians. The study included parents of patients with the NC form of CAH, positive for the p.V282L mutation (N = 55) and cadaveric donor samples (N = 231). All subjects were HLA-A, -B, and -DRB1 typed and tested for the presence of the p.V282L mutation. Among parents of patients, 92.73% of subjects were positive for the B*14:02 allele and almost half of them carried the HLA-A*33:01-B*14:02-DRB1*01:02 haplotype. Among cadaveric samples 77 out of 96 subjects positive for the B*14:02 allele had the p.V282L mutation. Among them, 37 were positive for the HLA-A*33:01-B*14:02-DRB1*01:02 haplotype, 23 had the HLA-A*33:01-B*14:02-DRB1*03:01 haplotype, 8 had the B*14:02-DRB1*01:02 combination and 5 were carrying the HLA-A*68:02-B*14:02-DRB1*13:03 haplotype. Only 4 of these subjects were positive for the B*14:02 allele. HLA-B*14:02 was the only single allele with association that reached statistically significant P value (RR = 12.00; P = 0.0024). Haplotypes B*14:02-DRB1*01:02 (P < 0.001) and HLA-A*68:02-B*14:02-DRB1*13:03 (P < 0.001) as well as HLA-A*33:01-B*14:02-DRB1*01:02 and HLA-A*33:01-B*14:02-DRB1*03:01 showed high relative risks (RR = 45.00, RR = 41.63 and RR = 36.96, respectively). Our data support the previously documented association of the HLA-A*33:01-B*14:02-DRB1*01:02 haplotype with the p.V282L mutation, but also point out a high frequency of the p.V282L mutation among Croatians with HLA-A*33:01-B*14:02-DRB1*03:01 and HLA-A*68:02-B*14:02-DRB1*13:03 haplotypes.

Low bone mineral density for age/osteoporosis in triple A syndrome-an overlooked symptom of unexplained etiology

Triple A syndrome (alacrima, achalasia, adrenal failure, progressive neurodegenerative disease) is caused by mutations in the AAAS gene which encodes the protein alacrima achalasia adrenal insufficiency neurologic disorder (ALADIN). Our investigation suggests that low bone mineral density (BMD) for age/osteoporosis could be a common but overlooked symptom of unexplained etiology in this rare multisystemic disease.

INTRODUCTION

The purpose of this study is to evaluate incidence and etiology of BMD for age/osteoporosis, a possibly overlooked symptom in triple A syndrome.

METHODS

Dual-energy X-ray absorptiometry (DXA) of the femoral neck, total hip, lumbar spine, and radius, bone turnover markers, minerals, total alkaline phosphatase (ALP), 25-hydroxy vitamin D (25-OHD), 1,25-dihydroxy vitamin D (1,25-OH2D), intact parathyroid hormone (PTH), and adrenal androgens (dehydroepiandrosterone sulfate (DHEAS) and androstenedione) were measured in five male and four female patients.

RESULTS

At time of diagnosis, low BMD for age was suspected on X-ray in seven of nine patients aged 2-11 years (not performed in two patients); normal levels of minerals and ALP were found in nine patients and low levels of adrenal androgens in eight patients (not measured in one patient). Reevaluation 5-35 years after introduction of 12 mg/m(2)/day hydrocortisone showed low BMD for age in two children, osteopenia in one, and osteoporosis in six adults. Normal levels of minerals, ALP, PTH, 1,25-OH2D, procollagen type 1, crosslaps, and osteocalcin were found in all patients. Low levels of adrenal androgens were found in all and 25OHD deficiency in six patients. Body mass index was <25 % for age and sex in eight of nine patients.

CONCLUSION

Low BMD for age/osteoporosis in our patients probably is not a result of glucocorticoid therapy but could be the consequence of low level of adrenal androgens, neurological impairment causing physical inactivity, inadequate sun exposure, and protein malnutrition secondary to achalasia. Considering ubiquitous ALADIN expression, low BMD/osteoporosis may be a primary phenotypic feature of the disease. Besides optimizing glucocorticoid dose, physical activity, adequate sun exposure, appropriate nutrition, and vitamin D supplementation, therapy with DHEA should be considered.

Incidence of type 1 diabetes mellitus in 0 to 14-yr-old children in Croatia--2004 to 2012 study

BACKGROUND

The incidence of type 1 diabetes mellitus (T1DM) among children and adolescents increased during the last 50 yr. The T1DM incidence in Croatia was 8.87/100.000/yr over 1995-2003, with an annual increase of 9%, which placed Croatia among countries with moderate risk for T1DM.

AIM

To investigate incidence rates and trends of T1DM from 2004 to 2012 in 0 to 14-yr-old Croatian children, and to compare the results with previous studies in Croatia and other European countries.

METHODS

T1DM crude incidence rates are estimated for the entire group and three subgroups: 0-4, 5-9, and 10-14 yr. Standardized incidence is calculated using the method of direct standardization according to World Health Organization (WHO) standard world population. The incidence rates by gender, age groups, seasonality, and calendar year, and their interactions were analyzed using Poisson regression model.

RESULTS

A total of 1066 cases were ascertained over 2004-2012. The standardized incidence was 17.23/100.000/yr (95% CI: 16.19-18.26), with no significant differences in incidence rates or trends between boys and girls. Statistically significant annual increase of 5.87% (p < 0.001) was found for the whole group, and for the subgroups 5-9 yr (6.82%; p < 0.001) and 10-14 yr (7.47%; p < 0.001). In the youngest subgroup (0-4 yr), annual increase was lower (2.43%; p = 0338) and not statistically significant.

CONCLUSION

The incidence of childhood T1DM is increasing in Croatia, thus placing Croatia among countries with high risk for T1DM. The annual increment of 5.87% is considerably lower than 9.0% reported earlier, but still higher than the European average (3.9%). The increase in incidence ceased in youngest children.

Autosomal-Recessive Mutations in SLC34A1 Encoding Sodium-Phosphate Cotransporter 2A Cause Idiopathic Infantile Hypercalcemia

Idiopathic infantile hypercalcemia (IIH) is characterized by severe hypercalcemia with failure to thrive, vomiting, dehydration, and nephrocalcinosis. Recently, mutations in the vitamin D catabolizing enzyme 25-hydroxyvitamin D3-24-hydroxylase (CYP24A1) were described that lead to increased sensitivity to vitamin D due to accumulation of the active metabolite 1,25-(OH)2D3. In a subgroup of patients who presented in early infancy with renal phosphate wasting and symptomatic hypercalcemia, mutations in CYP24A1 were excluded. Four patients from families with parental consanguinity were subjected to homozygosity mapping that identified a second IIH gene locus on chromosome 5q35 with a maximum logarithm of odds (LOD) score of 6.79. The sequence analysis of the most promising candidate gene, SLC34A1 encoding renal sodium-phosphate cotransporter 2A (NaPi-IIa), revealed autosomal-recessive mutations in the four index cases and in 12 patients with sporadic IIH. Functional studies of mutant NaPi-IIa in Xenopus oocytes and opossum kidney (OK) cells demonstrated disturbed trafficking to the plasma membrane and loss of phosphate transport activity. Analysis of calcium and phosphate metabolism in Slc34a1-knockout mice highlighted the effect of phosphate depletion and fibroblast growth factor-23 suppression on the development of the IIH phenotype. The human and mice data together demonstrate that primary renal phosphate wasting caused by defective NaPi-IIa function induces inappropriate production of 1,25-(OH)2D3 with subsequent symptomatic hypercalcemia. Clinical and laboratory findings persist despite cessation of vitamin D prophylaxis but rapidly respond to phosphate supplementation. Therefore, early differentiation between SLC34A1 (NaPi-IIa) and CYP24A1 (24-hydroxylase) defects appears critical for targeted therapy in patients with IIH.

Successful treatment of diffuse large B-cell non-hodgkin lymphoma with modified CHOP (cyclophosphamide/doxorubicin/vincristine/prednisone) chemotherapy and rituximab in a patient with Nijmegen syndrome

A 17-year-old Croatian boy with Nijmegen breakage syndrome (NBS) who developed diffuse large B-cell non-Hodgkin lymphoma is presented. The majority of the patients with this rare autosomal recessive disease are of Slavic origin and, in most of them, the disease is caused by NBS1 mutation 657del5, as was found in our patient. Nijmegen breakage syndrome is characterized by microcephaly, growth retardation, abnormal facial appearance, spontaneous chromosomal rearrangements, immunodeficiency, and a high predisposition to cancer development, predominantly lymphoma. Because of increased sensitivity to radiation therapy and chemotherapy, the treatment of malignancies in patients with NBS can be difficult. To our knowledge, our patient is the first with NBS reported in the literature who was successfully treated for diffuse large B-cell lymphoma with the anti-CD20 monoclonal antibody rituximab in addition to a modified dose of CHOP (cyclophosphamide/doxorubicin/vincristine/prednisone) chemotherapy. He has been in complete remission for 3 years after finishing the treatment.

Report of fertility in a woman with a predominantly 46,XY karyotype in a family with multiple disorders of sexual development

CONTEXT

We report herein a remarkable family in which the mother of a woman with 46,XY complete gonadal dysgenesis was found to have a 46,XY karyotype in peripheral lymphocytes, mosaicism in cultured skin fibroblasts (80% 46,XY and 20% 45,X) and a predominantly 46,XY karyotype in the ovary (93% 46,XY and 6% 45,X).

PATIENTS

A 46,XY mother who developed as a normal woman underwent spontaneous puberty, reached menarche, menstruated regularly, experienced two unassisted pregnancies, and gave birth to a 46,XY daughter with complete gonadal dysgenesis.

RESULTS

Evaluation of the Y chromosome in the daughter and both parents revealed that the daughter inherited her Y chromosome from her father. Molecular analysis of the genes SOX9, SF1, DMRT1, DMRT3, TSPYL, BPESC1, DHH, WNT4, SRY, and DAX1 revealed normal male coding sequences in both the mother and daughter. An extensive family pedigree across four generations revealed multiple other family members with ambiguous genitalia and infertility in both phenotypic males and females, and the mode of inheritance of the phenotype was strongly suggestive of X-linkage.

CONCLUSIONS

The range of phenotypes observed in this unique family suggests that there may be transmission of a mutation in a novel sex-determining gene or in a gene that predisposes to chromosomal mosaicism.

Daughter and her mildly affected father with Keipert syndrome

A 10-year-old girl with characteristic features of Keipert syndrome (broad terminal phalanges, especially of the thumb and hallux, sensorineural deafness, unusual facial features, large head circumference, maxillary hypoplasia, hoarse voice) and her mildly affected father (broad terminal phalanges, especially of the thumb and hallux, large head circumference, maxillary hypoplasia, and hoarse voice) are presented. The girl is the first reported female with this rare syndrome to date, and the fact that she probably inherited the disease from her father suggests an autosomal dominant pattern of inheritance.

Five Patients with Congenital Adrenal Hyperplasia due to 21-Hydroxylase Deficiency (One with Associated Neuroblastoma) Discovered in Three Generations of One Family

BACKGROUND

Most patients with 21-hydroxylase deficiency (21-OHD) are compound heterozygous carriers. Their phenotype usually reflects a less severe allelic mutation, although discordance between the genotype and the phenotype has been observed.

CASE REPORT

We present 5 patients with congenital adrenal hyperplasia (CAH) due to 21-OHD belonging to the 3 generations of the same family (grandmother, parents and their 2 children). As each patient carries at least one mild mutation of the CYP21 gene, their genotypes correspond to nonclassical CAH. The propositus is the older brother, who is compound heterozygous with a mild and severe CYP21 mutation (P30L/R356W). In spite of one mild CYP21 mutation, he presented with the clinical picture of a simple virilizing form of 21-OHD and required glucocorticoid replacement therapy from the age of 4. Both probands' parents are compound heterozygous carriers of different CYP21 gene mutations causing various degrees of enzymatic activity impairment, which explains the different genotypes and phenotypes in their offspring. The probands' mother, besides the nonclassical 21-OHD, also had neuroblastoma of the adrenal gland.

CONCLUSION

The potential discordance between the genotype and the phenotype in some patients with CAH is emphasized. The existence of a mild CYP21 mutation P30L in a compound heterozygous with CAH might be associated with progressive virilization requiring glucocorticoid therapy from early childhood. The occurrence of neuroblastoma with 21-OHD may support the hypothesis that an impairment in the synthesis and secretion of glucocorticoids may play role in the development and functioning of the adrenal medulla.

Deficiency of UBR1, a ubiquitin ligase of the N-end rule pathway, causes pancreatic dysfunction, malformations and mental retardation (Johanson-Blizzard syndrome)

Johanson-Blizzard syndrome (OMIM 243800) is an autosomal recessive disorder that includes congenital exocrine pancreatic insufficiency, multiple malformations such as nasal wing aplasia, and frequent mental retardation. We mapped the disease-associated locus to chromosome 15q14-21.1 and identified mutations, mostly truncating ones, in the gene UBR1 in 12 unrelated families with Johanson-Blizzard syndrome. UBR1 encodes one of at least four functionally overlapping E3 ubiquitin ligases of the N-end rule pathway, a conserved proteolytic system whose substrates include proteins with destabilizing N-terminal residues. Pancreas of individuals with Johanson-Blizzard syndrome did not express UBR1 and had intrauterine-onset destructive pancreatitis. In addition, we found that Ubr1(-/-) mice, whose previously reported phenotypes include reduced weight and behavioral abnormalities, had an exocrine pancreatic insufficiency, with impaired stimulus-secretion coupling and increased susceptibility to pancreatic injury. Our findings indicate that deficiency of UBR1 perturbs the pancreas' acinar cells and other organs, presumably owing to metabolic stabilization of specific substrates of the N-end rule pathway.

Pregnancy outcomes in women with classical congenital adrenal hyperplasia due to 21-hydroxylase deficiency

OBJECTIVE

Despite earlier detection, treatment, and surgical advances, fertility prognosis in women with classical 21-hydroxylase deficiency (21-OHD) is still low, especially in the salt-wasting (SW) form.

PATIENTS AND METHODS

We analysed the course and outcome of four pregnancies in two simple virilizing (SV) and one SW patient.

RESULTS

The evaluation of carrier status indicated that all three fathers had two normal CYP21 genes. During the pregnancy, the dose of prednisolone was increased in one of the SV patients and the SW patient. In the SW patient who developed pre-eclampsia, the dose of fludrocortisone was also increased. Three patients gave birth to a total of four healthy girls who were heterozygotes for 21-OHD with normal genitalia (one by vaginal delivery and three by Caesarean section). Family studies revealed that the mother of the SW patient has nonclassical 21-OHD.

CONCLUSION

Improving a low birth rate in females with SW 21-OHD remains a problem and new approaches are required. If the mother has 21-OHD (even nonclassical 21-OHD), pre-conception counselling and paternal genotyping are advisable and prenatal dexamethasone therapy should be considered.

Alteration of DNA binding, dimerization, and nuclear translocation of SHOX homeodomain mutations identified in idiopathic short stature and Leri-Weill dyschondrosteosis

Haploinsufficiency of the short stature homeobox gene SHOX has been found in patients with idiopathic short stature (ISS) and Leri-Weill dyschondrosteosis (LWD). In addition to complete gene deletions and nonsense mutations, several missense mutations have been identified in both patient groups, leading to amino acid substitutions in the SHOX protein. The majority of missense mutations were found to accumulate in the region encoding the highly conserved homeodomain of the paired-like type. In this report, we investigated nine different amino acid exchanges in the homeodomain of SHOX patients with ISS and LWD. We were able show that these mutations cause an alteration of the biological function of SHOX by loss of DNA binding, reduced dimerization ability, and/or impaired nuclear translocation. Additionally, one of the mutations (c.458G>T, p.R153L) is defective in transcriptional activation even though it is still able to bind to DNA, dimerize, and translocate to the nucleus. Thus, we demonstrate that single missense mutations in the homeodomain fundamentally impair SHOX key functions, thereby leading to the phenotype observed in patients with LWD and ISS.

Nonclassic 21-hydroxylase deficiency in Croatia

This is the first report of nonclassic congenital adrenal hyperplasia due to 21-hydroxylase (21-OH) deficiency in Croatia in which the patients have been evaluated clinically, hormonally, and by molecular genetic analysis. Genetic analysis was performed on 18 Croatian patients with nonclassic CAH due to 21-OH deficiency using allele-specific PCR. ACTH stimulation testing and HLA typing were used to evaluate patients hormonally. Molecular genetic analysis revealed a variety of mutations in individuals with different clinical symptoms, including precocious pubarche, hirsutism, (dysmenorrhea, subfertility and clitoromegaly. Serum stimulated 17-hydroxyprogesterone (17-OHP) levels indicated that all patients fell within the acceptable range for nonclassic congenital adrenal hyperplasia. Clinical and genetic analysis confirmed nonclassic 21-OH deficiency in our Croatian sample of ten males and eight females. This study shows that genotype does not necessarily predict fertility status in our group of affected patients.

Extraovarian steroid cell tumor 'not otherwise specified' as a rare cause of virilization in twelve-year-old girl

BACKGROUND

We present a 12-year-old girl with a 5-year history of progressive virilization.

RESULTS

Regarding elevated plasma levels of 17-hydroxyprogesterone (17-OHP) and androgens, normal ultrasound and CT scan of ovaries and adrenal glands, the nonclassic form of congenital adrenal hyperplasia (CAH) due to 21-hydroxylase deficiency was presumed the cause of virilization. As the glucocorticoid therapy did not normalize high levels of 17-OHP and androgens, and the DNA analysis did not demonstrate a mutation causing CAH, a laparotomy was performed. Near the right ovary a tumor was found and extirpated. Pathohistological studies determined it to be a rare steroid cell tumor, 'not otherwise specified'. Within the next months the signs of virilization resolved and menarche occurred.

CONCLUSIONS

Steroid cell tumor should be considered in differential diagnosis of virilization in childhood. Regarding the age of our patient and pathohistological findings of the tumor, her prognosis is favorable.

Congenital adrenal hyperplasia (21-hydroxylase deficiency) without demonstrable genetic mutations

Congenital adrenal hyperplasia (CAH) owing to 21-hydroxylase deficiency (21-OHD) is the most common inherited defect of adrenal steroid biosynthesis. At least 36 mutations in the CYP21 gene, which is mapped to chromosome 6p21.3, have been described. We performed genetic analysis of the CYP21 gene in a patient with classic 21-OHD CAH and her family. The entire exonic coding regions and intronic regions, as well as the -1 kb 5' upstream promoter region, were thoroughly sequenced and analyzed. Despite extensive sequencing, no mutation was found in this 3.7 kb area. The 11beta-hydroxylase defect, closely mimicking the clinical and biochemical phenotype of classic 21-OHD, was excluded by directly sequencing 2.6 kb covering the entire coding of the CYP11B1 gene. Herein we describe a phenotypically and hormonally affected patient with classic simple virilizing 21-OHD CAH who lacks a mutation in the entire CYP21 gene and coding region of the CYP11B1 gene.

Prenatal diagnosis of congenital adrenal hyperplasia (21-hydroxylase deficiency) in Croatia

We report on the prenatal diagnosis of congenital adrenal hyperplasia due to 21-hydroxylase in 20 at-risk pregnancies (16 salt-wasting and 4 simple virilizing families). We have diagnosed 3 affected fetuses (2 males and 1 female), 3 healthy homozygotes (2 males and 1 female), and 14 healthy heterozygotes (7 females and 7 males). These data were collected over 4 years. In 16 fetuses, the diagnosis was made with measurements of 17-hydroxyprogesterone (17-OHP) and delta-4-androstenedione (delta) in amniotic fluid (AF), human leukocyte antigen (HLA) typing of amniotic cells, as well as karyotypes between the 16th and 18th weeks of gestation. In 4 fetuses, DNA analysis of amniotic cells was also performed. In 3 pregnancies in which affected fetuses were suspected (on the basis of HLA typing and measurements of 17-OHP and delta concentrations in AF), the fetuses were electively aborted between the 17th to 19th weeks of gestation by parental decision. In all aborted fetuses, diagnosis was confirmed with HLA typing, autopsy findings of hyperplastic adrenal glands, and ambiguous genitalia in female fetuses. Postnatal diagnosis was confirmed in healthy fetuses with HLA typing and serum measurements of 17-OHP concentrations, and in 4 of them with DNA analysis. In 3 of the 4 families, DNA analyses revealed the following mutations: in Family 1, the index case mutation was Intron 2, Exon 3/Exon 6, and the fetus was Normal/Exon 6; in Family 2, the index case mutation was Ex1 Int2 Ex3/ Int2, and the fetus was Ex1 Int2 Ex3/Normal; and in Family 3, the index case mutation was Ex8(356)/Ex8(356), and the fetus was Ex8(356)/ Normal. We also report one case of prenatal diagnosis and treatment. Dexamethasone 0.5 mg BID (20 micrograms/kg/d) was given starting at 6th week of gestation. Prenatal diagnosis suggested, but did not prove, that the female fetus was a heterozygote as the fetus lacked the paternal mutation Ex8(318). No mutation was found in the mother. The fetus, the mother, and the affected sib shared a haplotype, further suggesting heterozygosity. The unaffected status was confirmed postnatally.

Apolipoprotein E phenotypes and genotypes as determined by polymerase chain reaction using allele-specific oligonucleotide probes and the amplification refractory mutation system in children with insulin-dependent diabetes mellitus

The frequency of apolipoprotein E (apo E) phenotypes and genotypes due to allelic variation at amino acids 112 and 158 was analysed in 50 children with type I diabetes. Phenotypes were determined by isoelectric focusing and genotypes by the technique of polymerase chain reaction using allele-specific oligonucleotide probes (PCR/ASO) and the amplification refractory mutation system (ARMS). Discrepancies between phenotypes and genotypes as assigned by PCR/ASO were observed in 12 (24%) cases and by ARMS in eight (16%) cases. Results revealed the apo E3/3 genotype, as assigned by ARMS, to be the most frequent one (70%), followed by apo E3/4 in 16%, apo E2/2 in 2%, apo E2/3 in 8%, apo E2/4 in 2% and apo E4/4 in 2% of the cases. Apo E3/4 genotype and phenotype were more frequently present in the children with type I diabetes as compared with the diabetic adults previously reported on.

Neurological and adrenal dysfunction in the adrenal insufficiency/alacrima/achalasia (3A) syndrome

Review of 20 patients with glucocorticoid deficiency (three cases also with salt loss) associated with absent tear secretion (19 cases) and achalasia of the cardia (15 cases) revealed neurological abnormalities in 17 including hyper-reflexia, muscle weakness, dysarthria, and ataxia together with impaired intelligence and abnormal autonomic function, particularly postural hypotension. These findings indicate that significant neurological problems are common in this multisystem disorder.

Sparse hair and multiple endocrine disorders in two women heterozygous for adrenoleukodystrophy

We describe two sisters (40 and 42 years old) heterozygous for adrenoleukodystrophy who have multiple endocrine disorders. In addition to the characteristic neurological symptoms, the younger patient has Addison disease and primary hypothyroidism attributable to autoimmune thyroiditis, and the older one has Graves disease. Both patients have loss of body hair and sparse scalp hair, which have not been reported previously in women heterozygous for adrenoleukodystrophy. After the institution of glucocorticoid replacement therapy, the younger sister, who has adrenal insufficiency, has shown unexpected neurological improvement.

A mutation (Pro-30 to Leu) in CYP21 represents a potential nonclassic steroid 21-hydroxylase deficiency allele

The mild nonclassic form of steroid 21-hydroxylase deficiency is one of the most common autosomal recessive disorders in humans, occurring in almost 1% of caucasians and about 3% of Ashkenazi Jews. Many patients with this disorder carry a Val-281----Leu missense mutation in the CYP21 gene. This and most other mutations causing 21-hydroxylase deficiency are normally present in the CYP21P pseudogene and have presumably been transferred to CYP21 by gene conversion. To identify other potential nonclassic alleles, we used recombinant vaccinia virus to express two mutant enzymes carrying the mutations Pro-30----Leu (normally present in CYP21P) and Ser-268----Thr (considered a normal polymorphism of CYP21). Whereas the activity of the protein carrying the Ser----Thr mutation was indeed indistinguishable from the wild type, the enzyme with the Pro----Leu substitution had 60% of wild-type activity for 17-hydroxyprogesterone and about 30% of normal activity for progesterone when assayed in intact cells. When kinetic analysis of the latter mutant enzyme was performed in cellular lysates, the first order rate constants (maximum velocity/dissociation constant) for both substrates were reduced 10- to 20-fold compared with those for the wild-type enzyme. Pro-30 is conserved in many microsomal P450 enzymes and may be important for proper orientation of the enzyme with respect to the aminoterminal transmembrane segment. The Pro----Leu mutation was present in 5 of 18 patients with nonclassic 21-hydroxylase deficiency, suggesting that this mutation indeed acts as a nonclassic deficiency allele.

Hormones and handedness: left-hand bias in female congenital adrenal hyperplasia patients

An excess of left-handers among males has been attributed to early androgen exposure. This theory was supported by our observation that girls with congenital adrenal hyperplasia (CAH) are more left-biased than their normal sisters. Male CAH patients, with prenatal androgen exposure similar to that of unaffected brothers, had typical male-handedness patterns.

Premature thelarche: a possible adrenal disorder

Endocrine studies in girls with precocious thelarche were compared with those of normal girls of similar ages. Girls with precocious thelarche showed breast development and oestrogenised vaginal smears as the only signs of precocious sexual development. A few of the girls were tall and some had advanced bone ages but these two findings were not consistently present in the same patient. Hormones--such as serum oestradiol, oestrone, delta 4-androstenedione, progesterone, dehydroepiandrosterone (DHEA), follicle-stimulating hormone, luteinising hormone, and prolactin, and urinary 17-ketosteroids--were measured. Only DHEA was different, being higher in girls with precocious thelarche. It is suggested that the high DHEA level may serve as a precursor for conversion to oestrogens in target tissues, breast, and vagina. This mechanism for oestrogenisation had been reported in other patients.

A liver urocanase deficiency

Two sisters with a rare inborn error of histidine metabolism resulting from urocanase deficiency are being presented. The more common form of familial histidinemia due to histidase deficiency is excluded. The urocanase deficiency is proven by demonstrating increased excretion of metabolites of the product of the urocanase enzyme action. Further, the strongest evidence for the urocanase defect rests on the demonstration of urocanase deficiency and normal histidase activity in liver.