Can Non-Coding NR5A1 Gene Variants Explain Phenotypes of Disorders of Sex Development?

INTRODUCTION

NR5A1 is an essential transcription factor that regulates several target genes involved in reproduction and endocrine function. Pathogenic variants in this gene are responsible for a wide spectrum of disorders/differences of sex development (DSD).

METHODS

The molecular study involved Sanger sequencing, in vitro assays, and whole exome sequencing (WES).

RESULTS

Four variants were identified within the NR5A1 non-coding region in 3 patients with 46,XY DSD. In vitro analyses showed that promoter activity was affected in all cases. WES revealed variants in SRA1, WWOX, and WDR11 genes.

DISCUSSION/CONCLUSION

Evaluation of clinical and phenotypic significance of variants located in a non-coding region of a gene can be complex, and little is known regarding their association with DSD. Nevertheless, based on the important region for interaction with cofactors essential to promote appropriated sex development and on our in vitro results, it is feasible to say that an impact on gene expression can be expected and that this may be correlated with the DSD pathophysiology presented in our patients. Considering the number of cases that remain elusive after screening for the well-known DSD related genes, we emphasize the importance of a careful molecular analysis of NR5A1 non-coding region which is commonly neglected and might explain some idiopathic DSD cases.

Suggested Cutoff Point for Testosterone by Liquid Chromatography with Tandem Mass Spectrometry (LC-MS/MS) after Stimulation with Recombinant Human Chorionic Gonadotropin

The human chorionic gonadotropin (hCG) stimulation test that evaluates gonadal steroidogenesis is crucial in the assessment of patients with 46,XY disorders of sex development (DSD). This study aimed to determine a testosterone (T) cutoff level that indicates an adequate testicular function using LC-MS/MS after stimulation with recombinant human chorionic gonadotropin (rhCG) in a single dose. Nineteen prepubertal children with 46,XY DSD and normal T secretion were evaluated. T and dihydrotestosterone (DHT) levels were measured by liquid chromatography technique with tandem mass spectrometry (LC-MS/MS) before and 7 days after rhCG application at 250 µg. We suggest 0.89 ng/mL as the cutoff point for T after rhCG stimulation analyzed by LC-MS/MS.

Trends in Time Regarding Sex Assignment of Patients with Disorders of Sex Development: Experience of an Interdisciplinary Service

INTRODUCTION

The aim of this retrospective study was to verify the association between the time of diagnosis and initial and final sex assignment in a disorder of sex development (DSD) diagnostic group, looking at the age of the patients at first visit, severity of genital ambiguity, and karyotype.

METHODS

The time of diagnosis was divided into 3 groups: before 2000, between 2000 and 2006, and after 2006. Data were categorized and analyzed using the χ2 test with α < 0.05.

RESULTS

A total of 567 cases were analyzed; 307 were assigned as male, 135 as female, and 125 remained undefined at the first visit. After clinical and laboratory evaluations, 369 patients were male and 198 were female. Neither initial nor final sex assignment proportions changed over time, but there were significant differences in the age at first visit, with referral occurring at an earlier age, as well as more severe genital ambiguity presentations, a higher proportion of sex chromosome aberrations, and a lower frequency of 46,XX DSD cases. This occurred both in the sample as a whole (567 cases) and in the group of 125 patients without definitive sex assignment at the first visit. The results were similar when only 284 patients aged less than 12 months at the first visit were analyzed.

DISCUSSION/CONCLUSION

Over time, there were no changes in sex assignment proportions, but there was an increased awareness of the need for early referral and changes in clinical, cytogenetic, and diagnostic aspects.

Sex dimorphism of weight and length at birth: evidence based on disorders of sex development

BACKGROUND

Males have higher weight and length at birth than females.

AIM

To verify the influence of the Y chromosome and the action of intrauterine androgens on weight and length at birth of children with Disorders of Sex Development (DSD).

SUBJECTS AND METHODS

A cross-sectional and retrospective study. Patients with Turner syndrome (TS), complete (XX and XY), mixed (45,X/46,XY) and partial (XY) gonadal dysgenesis (GD), complete (CAIS) and partial (PAIS) androgen insensitivity syndromes and XX and XY congenital adrenal hyperplasia (CAH) were included. Weight and length at birth were evaluated.

RESULTS

Weight and length at birth were lower in TS and mixed GD when compared to XY and XX DSD cases. In turn, patients with increased androgen action (117 cases) had higher weight and length at birth when compared to those with absent (108 cases) and decreased (68 cases) production/action. In birthweight, there was a negative influence of the 45,X/46,XY karyotype and a positive influence of increased androgen and gestational age. In birth length, there was a negative influence of the 45,X and 45,X/46,XY karyotypes and also a positive influence of increased androgen and gestational age.

CONCLUSIONS

The sex dimorphism of weight and length at birth could possibly be influenced by intrauterine androgenic action.

Growth, puberty and testicular function in boys born small for gestational age with a nonspecific disorder of sex development

OBJECTIVE

Being born small for gestational age (SGA) is frequently associated with unexplained disorders of sex development (nonspecific DSD) in boys. Little is known about their future growth, puberty and testicular function. Our objective is to determine the long-term endocrine outcome of boys born SGA who have a nonspecific DSD.

DESIGN

Boys with a nonspecific DSD born SGA and appropriate for GA (AGA) were retrieved through the International Disorders of Sex Development registry and retrospective data collected, based on a spreadsheet containing 102 items.

PATIENTS AND MEASUREMENTS

In total, 179 boys were included, of which 115 were born SGA and 64 were born AGA. Their growth and pubertal development were compared. Serum LH, FSH, testosterone, AMH and inhibin B levels in infancy and puberty were analysed to assess testicular function.

RESULTS

At 2 years of age, 30% of SGA boys had incomplete or absent catch-up growth. Boys born SGA also had higher LH during minipuberty and lower testosterone in stimulation tests (p = 0.037 and 0.040, respectively), as compared to boys born AGA. No differences were observed in timing or course of puberty or end-pubertal hormone levels.

CONCLUSIONS

Almost one out of three SGA boys with a nonspecific DSD experiences insufficient catch-up growth. In addition, our data suggest dysfunction of infantile Leydig cells or altered regulation of the hypothalamic-pituitary-gonadal axis in SGA boys during childhood. Sex steroid production during puberty seems unaffected.

Association between Down Syndrome and Disorders of Sex Development: Report of Three Cases and Review of 188 Cases in the Literature

In this study, we present 3 cases of Down syndrome (DS) associated with disorders/differences of sex development (DSD) and review the literature on this topic. Case 1: 1-year-old child with male genitalia and DS phenotype, 47,XX,+21 karyotype and testicular DSD. Case 2: 11-month-old child with male genitalia and few DS dysmorphisms, 45,X/47,XY,+21 karyotype, and mixed gonadal dysgenesis. Case 3: 4-month-old child with female genitalia and DS phenotype, 47,XY,+21 karyotype and XY complete gonadal dysgenesis. In the literature, among 188 patients, 107 (57%) had Klinefelter syndrome and 61 (33%) Turner syndrome, 12 (6%) had mixed gonadal dysgenesis, 2 (1%) had partial androgen insensitivity, 2 (1%) ovotesticular DSD, and the others had congenital adrenal hyperplasia, XY partial gonadal dysgenesis, XY complete gonadal dysgenesis, and complete androgen insensitivity (1 case each). A typical DS phenotype was found in all individuals of the revision, with the exception of one case, but DSD features were not always reported. In conclusion, the association of DS with sex chromosome DSD is the most frequently observed, whereas associations with 46,XX and 46,XY DSD is extremely rare.

Screening of targeted panel genes in Brazilian patients with primary ovarian insufficiency

Primary ovarian insufficiency (POI) is a heterogeneous disorder associated with several genes. The majority of cases are still unsolved. Our aim was to identify the molecular diagnosis of a Brazilian cohort with POI. Genetic analysis was performed using a customized panel of targeted massively parallel sequencing (TMPS) and the candidate variants were confirmed by Sanger sequencing. Additional copy number variation (CNV) analysis of TMPS samples was performed by CONTRA. Fifty women with POI (29 primary amenorrhea and 21 secondary amenorrhea) of unknown molecular diagnosis were included in this study, which was conducted in a tertiary referral center of clinical endocrinology. A genetic defect was obtained in 70% women with POI using the customized TMPS panel. Twenty-four pathogenic variants and two CNVs were found in 48% of POI women. Of these variants, 16 genes were identified as BMP8B, CPEB1, INSL3, MCM9, GDF9, UBR2, ATM, STAG3, BMP15, BMPR2, DAZL, PRDM1, FSHR, EIF4ENIF1, NOBOX, and GATA4. Moreover, a microdeletion and microduplication in the CPEB1 and SYCE1 genes, respectively, were also identified in two distinct patients. The genetic analysis of eleven patients was classified as variants of uncertain clinical significance whereas this group of patients harbored at least two variants in different genes. Thirteen patients had benign or no rare variants, and therefore the genetic etiology remained unclear. In conclusion, next-generation sequencing (NGS) is a highly effective approach to identify the genetic diagnoses of heterogenous disorders, such as POI. A molecular etiology allowed us to improve the disease knowledge, guide decisions about prevention or treatment, and allow familial counseling avoiding future comorbidities.

Prevalence of genital abnormalities in neonates

OBJECTIVES

To assess the prevalence of genital abnormalities among neonates in two public maternity-schools.

METHODS

Case-control, cross-sectional descriptive study. Genital morphology of 2,916 neonates was assessed using a clinical protocol between 04/19/2010 and 04/18/2011. Control group included neonates without birth defects, born at the same maternity unit and in the same day in which a case was identified. Fisher and Kruskal-Wallis tests were used for statistics.

RESULTS

The study identified 29 (1:100) neonates with genital abnormalities. Most of them were examined within 3 days of life and presented only one genital defect. Morphological abnormalities comprised: genital ambiguity (1/29), fusion of labia majora (1/29), micropenis (2/29), enlarged clitoris (6/29), hypospadia (9/29), and combined defects (4/29). Only one case reported the genital abnormality in the statement of live birth correctly. Prematurity occurred in 13/29 cases and was the only variable statistically associated with genital defects. Eight cases agreed on the complementary investigation of the genital defect, among which three were diagnosed with disorder of sex development.

CONCLUSIONS

There is a high prevalence of genital abnormalities in the maternity units included in the present study and most cases are under-diagnosed and under-reported. Our results reinforce the importance of a careful examination of genital morphology in neonatal period towards the recognition of minor defects that can be clinical features of a disorder of sex development.

OCT4 immunohistochemistry may be necessary to identify the real risk of gonadal tumors in patients with Turner syndrome and Y chromosome sequences

BACKGROUND

The aim of this study was to investigate the frequency of gonadal tumors among patients with Turner syndrome (TS) carrying Y-derivative sequences in their chromosomal constitution.

METHODS

Six out of 260 patients with TS were selected based on mosaicism of the entire Y chromosome; 10 were included because Y-derivative sequences have been detected by PCR with specific oligonucleotides (sex-determining region on the Y, testis specific-protein, Y and DYZ3) and further confirmed by FISH. The 16 patients were subjected to bilateral gonadectomy at ages varying from 8.7 to 18.2 years. Both histopathological investigation with hematoxylin and eosin (H&E) and immunohistochemical analysis with anti-octamer-binding transcription factor 4 (OCT4) antibody were performed.

RESULTS

Gonadal neoplasia was not detected in any of the 32 gonads evaluated by H&E; however, four gonads (12%) from three patients (19%) had positive OCT4 staining in 50-80% of nuclei, suggesting the existence of germ cell tumors (gonadoblastoma or in situ carcinoma).

CONCLUSIONS

Evaluation of the real risk of development of gonadal tumors in TS patients with Y-derivative sequences in their chromosomal constitution may require a specific histopathological study, such as immunohistochemistry with OCT4.

The novel p.E89K mutation in the SRY gene inhibits DNA binding and causes the 46,XY disorder of sex development

Male sex determination in humans is controlled by the SRY gene, which encodes a transcriptional regulator containing a conserved high mobility group box domain (HMG-box) required for DNA binding. Mutations in the SRY HMG-box affect protein function, causing sex reversal phenotypes. In the present study, we describe a 19-year-old female presenting 46,XY karyotype with hypogonadism and primary amenorrhea that led to the diagnosis of 46,XY complete gonadal dysgenesis. The novel p.E89K missense mutation in the SRY HMG-box was identified as a de novo mutation. Electrophoretic mobility shift assays showed that p.E89K almost completely abolished SRY DNA-binding activity, suggesting that it is the cause of SRY function impairment. In addition, we report the occurrence of the p.G95R mutation in a 46,XY female with complete gonadal dysgenesis. According to the three-dimensional structure of the human SRY HMG-box, the substitution of the conserved glutamic acid residue by the basic lysine at position 89 introduces an extra positive charge adjacent to and between the positively charged residues R86 and K92, important for stabilizing the HMG-box helix 2 with DNA. Thus, we propose that an electrostatic repulsion caused by the proximity of these positive charges could destabilize the tip of helix 2, abrogating DNA interaction.

Effects of growth hormone on body proportions in Turner syndrome compared with non-treated patients and normal women

BACKGROUND

The majority of anthropometric assessments in Turner syndrome (TS) patients has focused on height.

AIM

To analyze body proportions in young adult TS patients either treated or not treated with rhGH, and to compare them with a group of age-matched healthy women.

SUBJECTS AND METHODS

Standing height, sitting height, weight, foot and leg lengths, arm span, head circumference, biliac and biacromial diameters were measured in 52 non-treated TS patients, 30 treated with rhGH and 133 healthy women.

RESULTS

Age at the start of rhGH therapy varied from 7.8 to 15.1 yr (10.0±1.3 yr), the duration of treatment from 2.8 to 8.2 yr (3.7±1.5 yr) and the mean recombinant human GH (rhGH) dose was 0.42 mg/kg/week (from 0.32 to 0.50 mg/kg/week). Nontreated patients did not show any difference in anthropometric variables when compared with the treated ones, except for hand length (p=0.02) and height (p=0.05), which were increased in the treated group. All anthropometric variables, except head circumference, were different when comparing TS patients (either treated or not) with age-matched healthy women.

CONCLUSION

Brazilian TS patients either treated or not with rhGH showed almost no differences in terms of their body proportions. This result is probably due to the late age at the start of treatment, and/or the short period of rhGH administration. Hand length was different between the groups, showing the importance of including the extremities in body proportion assessment during rhGH treatment of TS patients.

Congenital perineal lipoma presenting as ambiguous genitalia

BACKGROUND

Congenital perineal lipoma is extremely rare and may lead to a misdiagnosis of ambiguous genitalia.

CASE REPORTS

We report on two girls referred to our service for ambiguous genitalia. Patient 1 (17 days old) and patient 2 (2 months old) had unremarkable gestational and perinatal histories. Both had normal female external genitalia and a 46,XX karyotype. Patient 1 had a polypoid, protruding 3.0 x 2.0 x 1.5-cm phallic-like mass arising at the inferior border of the left labium majora, and patient 2 had a similar mass of 1.5 x 1.5 x 1.0 cm at the same site and an imperforate anus. In both cases the mass was removed and found to be a lipoma.

DISCUSSION

To our knowledge, perineal lipoma has been reported only in eleven girls, nine of them with associated anorectal malformation. Migration and fusion of the labioscrotal folds and formation of the urorectal septum are simultaneous developmental events occurring in the same region, which may explain the association of perineal lipoma and anorectal malformations.

Allelic Frequencies of The 35delG Mutation of The GJB2 Gene in Different Brazilian Regions

Mutations in the GJB2 gene, which encodes the protein connexin 26, are a major cause of autosomal recessive deafness. The most frequent mutation, 35delG, has a carrier frequency as high as 4% in some countries, and this frequency varies in different ethnic groups. Most of the Brazilian population results from interethnic crosses of people from three continents (European, African, and Amerindian), and the proportion of each varies according to the geographical region of the country. To verify if the different ethnic composition of Brazilian regions leads to variable 35delG carrier frequencies, we performed the screening of the 35delG mutation using DNA from dried-blood filter paper samples obtained from 1,856 newborns from 10 cities in different regions. The 35delG mutation was found in 25 individuals (1.35%), indicating an overall carrier frequency of 1:74. This frequency was 1:47 in the north, 1:64 in the southeast, 1:85 in the south and 1:124 in the northeast, but these differences were not significant. The overall frequency of the 35delG allele was estimated as 0.0067, and comparison between expected and observed genotype frequencies indicates that the population is in Hardy-Weinberg equilibrium.

Female counterpart of shawl scrotum in Aarskog-Scott syndrome

Aarskog-Scott syndrome (ASS) is an X-linked disorder characterized by facial, skeletal and genital anomalies, including penoscrotal transposition in males. We report on a girl from a family with ASS who exhibits a transposition of the clitoris.

A rare case of aniridia and balanced translocation (5;11) (p15.3;q22) arising in the same subject: a challenge for genetic counseling

The authors report on a case of isolated aniridia caused by haploinsufficiency of the PAX6 gene, which is located on 11p13, and a balanced translocation t(5;l1)(p15.3;q22) inherited respectively from his father and his mother. Due to the coincidence of two abnormalities in the same chromosome, the segregation of the mutant allele leading to aniridia and of the chromosomes involved in the translocation are not independent events. Considering that both monosomy and trisomy for 11q22-qter are unviable, his offspring may inherit either the PAX6 mutation or the balanced translocation. However, depending on the occurrence of crossing over, there is a possibility for him to have normal offspring; on the other hand, he may also father children with both anomalies. This unusual case, in which the proband has a presumably very low chance of completely normal offspring, turned to be a challenge for genetic counseling.

Diagnosis of 5alpha-reductase type 2 deficiency: contribution of anti-Müllerian hormone evaluation

AIM

To evaluate anti-Müllerian hormone (AMH) levels in patients with clinical and molecular diagnosis of 5alpha-reductase 2 deficiency.

PATIENTS AND METHODS

Data from 14 patients whose age ranged from 21 days to 29 years were analyzed according to age and pubertal stage. Sexual ambiguity was rated as Prader III in 11 patients. LH, FSH, testosterone (T), dihydrotestosterone (DHT) and AMH serum levels were measured in all but two patients, who had been previously submitted to gonadectomy; T and DHT were also measured in 20 age-matched controls.

RESULTS

Gonadotropin levels were normal in all but one patient who retained gonads (six of whom had reached puberty) and T/DHT ratio was elevated in all patients when compared to controls. All prepubertal patients had AMH levels < -1 SD for age, while most pubertal patients had AMH levels compatible with pubertal stage.

CONCLUSIONS

Prepubertal patients with 5alpha-reductase 2 deficiency have AMH values in the lower part of the normal range. These data indicate that T does not need to be converted to DHT to inhibit AMH secretion by Sertoli cells.

A naturally occurring deletion in the SRY promoter region affecting the Sp1 binding site is associated with sex reversal

Male to female sex reversal results from failure of testis development. Mutations in the SRY gene or in other genes involved in the sexual differentiation pathway are considered to cause XY gonadal dysgenesis. The majority of the mutations in the SRY described so far are located within the SRY coding region, mainly in the HMG-box conserved domain. Comparison of 5' flanking SRY gene sequences among different species indicated the presence of several putative conserved consensus sequences for different transcription regulators. In this study, we investigated a 360 bp sequence encompassing the SRY putative core promoter, in 17 patients with variable degrees of 46,XY sex reversal, which have been previously shown not to bear mutations in the SRYcoding region. Sequencing analysis of the SRYpromoter in one patient with complete XY gonadal dysgenesis revealed a three base pair deletion in one of the Sp1 binding sites. The deletion abolished Sp1 binding in vitro. This is the first report on a naturally occurring mutation affecting the Sp1 regulatory element in the SRY promoter region, which is associated with sex reversal. Additionally, upon familial investigation the father, who had 18 genital surgeries due to severe hypospadia without cryptorchidism, was found to bear the same deletion and several relatives were referred to have sexual ambiguity.

Mutations in SRY and WT1 genes required for gonadal development are not responsible for XY partial gonadal dysgenesis

The WT1 transcription factor regulates SRY expression during the initial steps of the sex determination process in humans, activating a gene cascade leading to testis differentiation. In addition to causing Wilms' tumor, mutations in WT1 are often responsible for urogenital defects in men, while SRY mutations are mainly related to 46,XY pure gonadal dysgenesis. In order to evaluate their role in abnormal testicular organogenesis, we screened for SRY and WT1 gene mutations in 10 children with XY partial gonadal dysgenesis, 2 of whom with a history of Wilms' tumor. The open reading frame and 360 bp of the 5' flanking sequence of the SRY gene, and the ten exons and intron boundaries of the WT1 gene were amplified by PCR of genomic DNA. Single-strand conformation polymorphism was initially used for WT1 mutation screening. Since shifts in fragment migration were only observed for intron/exon 4, the ten WT1 exons from all patients were sequenced manually. No mutations were detected in the SRY 5' untranslated region or within SRY open-reading frame sequences. WT1 sequencing revealed one missense mutation (D396N) in the ninth exon of a patient who also had Wilms' tumor. In addition, two silent point mutations were found in the first exon including one described here for the first time. Some non-coding sequence variations were detected, representing one new (IVS4+85A>G) and two already described (-7ATG T>G, IVS9-49 T>C) single nucleotide polymorphisms. Therefore, mutations in two major genes required for gonadal development, SRY and WT1, are not responsible for XY partial gonadal dysgenesis.

Frequency of the 35delG Mutation in the GJB2 Gene in Samples of European, Asian, and African Brazilians

Mutations in the GJB2 gene are a major cause of congenital deafness. One specific mutation, the 35delG mutation, has accounted for most of the GJB2 mutations detected in European populations and is one of the most frequent disease mutations identified so far. We evaluated the frequency of the 35delG mutation in DNA samples from Brazilians of European, Asian, and African ancestry. All DNA samples were screened for the 35delG mutation using an allele-specific PCR. This study shows that the frequency of a common mutation (35delG) is significantly lower in non-European populations.

Novel mutations affecting SRY DNA-binding activity: the HMG box N65H associated with 46,XY pure gonadal dysgenesis and the familial non-HMG box R30I associated with variable phenotypes

The SRY gene (sex-determining region of the Y chromosome) initiates the process of male sex differentiation in mammalians. In humans mutations in the SRY gene have been reported to account for 10-15% of the XY sex reversal cases. We describe here two novel missense mutations in the SRY gene after the screening of 17 patients, including 3 siblings, with 46,XY gonadal dysgenesis and 4 true hermaphrodites. One of the mutations, an A to C transversion within the HMG box, causes the N65H substitution and it was found in a patient presenting 46,XY pure gonadal dysgenesis. The Escherichia coli expressed SRY(N65H) protein did not present DNA-binding activity in vitro. The other mutation, a G to T transversion, causes the R30I substitution. This mutation was found in affected and nonaffected members of a family, including the father, two siblings with partial gonadal dysgenesis, a phenotypic female with pure gonadal dysgenesis, and three nonaffected male siblings. The G to T base change was not found in the SRY sequence of 100 normal males screened by ASO-PCR. The R30I mutation is located upstream to the HMG box, within the (29)RRSSS(33) phosphorylation site. The E. coli expressed SRY(R30I) protein was poorly phosphorylated and consequently showed reduced DNA-binding capacity in vitro.

Deafness resulting from mutations in the GJB2 (connexin 26) gene in Brazilian patients

Congenital deafness occurs in approximately 1 in 1000 live births. In developed countries about 60% of hearing loss is genetic. However, in Brazil most cases of hearing loss are due to environmental factors, such as congenital infections (mainly rubella), perinatal anoxia, kernicterus and meningitis. Recently, it has been demonstrated that the GJB2 gene is a major gene underlying congenital sensorial deafness. Mutations in this gene cause 10-20% of all genetic sensory hearing loss. One specific mutation, 35delG, accounts for the majority of mutant alleles. The extent of the hearing impairment varies from mild/moderate to profound, even within the patients homozygous for the common 35delG mutation. There may also be progression with age. Mutation analysis in the GJB2 gene was performed on 36 families (group A) presenting with at least one individual with non-syndromic deafness (NSD). An unselected series of 26 deaf individuals referred by other services where the environmental factors were not completely excluded was also part of the study (group B). Mutations in the GJB2 gene were found in 22% (eight patients) of the families tested in group A, and 11.5% (three patients) of individuals within group B. This finding should facilitate diagnosis of congenital deafness and allow early treatment of the affected subjects.

A boy with mental retardation, blepharophimosis and hypothyroidism: a diagnostic dilemma between Young-Simpson and Ohdo syndrome

We report a male infant with an association of hypothyroidism and unusual facies, including blepharophimosis, which is similar to the dysmorphic features observed in the condition first described by Young and Simpson [(1987) J Med Genet 24:715-7161. On the other hand, the patient also shares many features with those reported as having Ohdo blepharophimosis syndrome [Ohdo et al, (1986) J Med Genet 23:242-244]. Previous case reports are reviewed and difficulties concerning the differential diagnosis of these conditions are discussed.

Evaluation of the tubular and interstitial functions of the testis in 46,XY patients with ambiguous genitalia

Investigation of the origin of sexual ambiguity is complex. Although testicular function has traditionally been assessed only by examining the steroidogenic capacity of Leydig cells and spermatogenesis, it has recently been shown that the measurement of serum anti-Müllerian hormone (AMH) as a marker of Sertoli cell function may also help clinicians. The aim of this study was to evaluate both Leydig and Sertoli cell functions in 46,XY patients with intersex states in order to establish biochemical patterns that would help to reach an etiologic diagnosis. We measured serum androgens, AMH and gonadotropins in 24 patients with sexual ambiguity and XY karyotype: 8 with gonadal dysgenesis (GD), 3 with 3beta-hydroxysteroid dehydrogenase deficiency (3betaHSD), 5 with androgen insensitivity syndrome (AIS), 4 with 5alpha-reductase 2 (SRD5A2) deficiency, and 4 were of unknown origin or idiopathic. Our results showed that while testosterone was low and gonadotropins elevated in patients with either GD or 3betaHSD, AMH was low in the former and high in the latter. Serum AMH and gonadotropins were normal or high in patients with 3betaHSD or AIS, but these could be distinguished by testosterone levels. Serum testosterone and gonadotropins were normal or high in AIS and SRD5A2 deficiency patients; however, while AMH was elevated in AIS, it was not the case in SRD5A2 deficiency patients, indicating that testosterone is sufficient to inhibit AMH within the testis. In idiopathic cases gonadotropins and testosterone were normal, and AMH was normal or low. We conclude that the combined measurement of androgens, AMH and gonadotropins helps to establish the diagnosis in intersex patients.

Turner's syndrome and thyroid disease: a transverse study of pediatric patients in Brazil

An increased prevalence of autoimmune thyroid disease (AITD) has been described in Turner's syndrome (TS), but the extent of this association is still controversial. Some studies also suggest that AITD is more frequent among patients with X-isochromosome. In order to determine the prevalence of AITD among girls with TS, and to look for an association with age and karyotype, we evaluated 71 patients with a mean age of 11.4 years (range 0-19.9). 15.5% (11/71) were hypothyroid, 17 (23.9%) were positive for thyroid peroxidase (TPO) and/or thyroglobulin (Tg) antibodies, and 24 (33.8%) had thyromegaly. No abnormality was observed before 4 years, and the highest frequencies were observed after 16 years. There were no significant differences concerning thyroid findings among patients with a 45,X karyotype, mosaics, and structural rearrangements. Half of the patients (35/71) exhibited one or more abnormalities, which demonstrates the importance of careful evaluation of thyroid function in all girls with TS.

New frameshift mutation in the 5alpha-reductase type 2 gene in a Brazilian patient with 5alpha-reductase deficiency

Male pseudohermaphroditism caused by steroid 5alpha-reductase deficiency is an autosomal recessive disorder. The enzyme steroid 5alpha-reductase 2 (encoded by the SRD5A2 gene) catalyses the conversion of testosterone to dihydrotestosterone, which is required for normal differentiation of the external male genitalia. This report describes the molecular analysis of the 5alpha-reductase type 2 gene in a Brazilian patient who was raised as a female, underwent a reversal of gender role behavior, and is now a married man. This patient is a compound heterozygote bearing an A-->G mutation within exon 2, changing codon 126 from Glu to Arg on one allele and a novel single base deletion (418delT) causing a frameshift mutation at codon 140 in the same exon, on the other allele. This last mutation probably leads to the synthesis of a truncated protein, because a premature termination signal is created at codon 159.

True hermaphrodites in the southeastern region of Brazil: a different cytogenetic and gonadal profile

Sex ambiguity may be due to several disorders of gonadal differentiation, including true hermaphroditism (TH), as well as male and female pseudohermaphroditism. Although TH is a rare cause of intersex in Europe and North America, in Africa it presents one of the highest frequencies. The 46,XX karyotype has been found in the majority of the reported patients (70.6%), and aberrations in the sex chromosomes have been observed in about 22% of the cases. The 46,XY karyotype has been described as less frequent. Herein we describe ten cases of TH which have been diagnosed over the last 7 years, six lateral TH, two unilateral TH, and two cases of ovotestes with absent contralateral gonad. From a total of 18 gonads analyzed, there were 8 testes, 6 ovaries and 4 ovotestes. Nine subjects had originally a male sex assignment, and in three cases this was reverted to female. Four cases had a 46,XY karyotype. Additional sex chromosome aberrations had been found in four different cases [two 46,XX/46,XY, one 45,X/47,XYY, one 46,X,del(Yq)]. A 46,XX karyotype was found in only two individuals, and both were SRY negative. Our preliminary data, especially on the constitution of chromosomes and gonads, indicate marked differences from those in the literature.

Mutations of androgen receptor gene in Brazilian patients with male pseudohermaphroditism

We describe the identification of point mutations in the androgen receptor gene in five Brazilian patients with female assignment and behavior. The eight exons of the gene were amplified by the polymerase chain reaction (PCR) and analyzed for single-strand conformation polymorphism (SSCP) to detect the mutations. Direct sequencing of the mutant PCR products demonstrated single transitions in three of these cases: G-->A in case 1, within exon C, changing codon 615 from Arg to His; G-->A in case 2, within exon E, changing codon 752 from Arg to Gln, and C-->T in case 3, within exon B, but without amino acid change.

Detection of Gly-196-Ser mutation in 5alpha-reductase type II gene in a Brazilian patient with female assignment and behavior

We describe the identification of a single base mutation in the 5alpha-reductase type II gene in a Brazilian patient who was reared as female and remained with female behavior and sexual identity.

Female pseudohermaphroditism due to classical 21-hydroxylase deficiency in a girl with Turner syndrome

We report on a rare case of female pseudohermaphroditism due to classical 21-hydroxylase deficiency associated with Turner syndrome (45,X/46,XX). Difficulties in the management of both diseases are briefly discussed. We regard this rare combination as a coincidental occurrence.

Cranio-oculo-fronto-nasal malformation: a new MCA condition?

We describe a boy born to non-consanguineous parents who presents a singular clinical picture characterized by severe mental retardation, craniosynostosis, ocular abnormalities, and frontonasal malformation. This seems to be a previously undescribed condition of unknown aetiology which should be mainly distinguished from craniofrontonasal dysplasia, and frontofacionasal dysostosis.

[Short stature and Turner syndrome: an association more frequent than expected]

Turner syndrome is a well-known cause of proportionately short stature in girls, but its frequency among these patients must vary in different populations. In Brazil, the cytogenetic study of 38 short girls without psychoneuromotor retardation, and without taking into account the presence or absence of dysmorphic signs, revealed that at least 1:8 had Turner syndrome. This is an unexpectedly high frequency ina population which is largely subject to adverse environmental conditions leading to growth deficiency.

True agonadism: report of a case analyzed with Y-specific DNA probes

We report on a 5-year-old girl with a male karyotype (46,XY), severe psychomotor and physical retardation, minor anomalies, and female external genitalia with a blindly ending vagina. She has normal adrenal function, prepubertal serum gonadotropin and testosterone levels, which did not rise after hCG stimulation. On abdominal exploration no gonads were found, and only mesonephric and Müllerian remnants. She was HY positive, and no deletion was detected in the Y chromosome using 5 different probes. Although a genetic defect is not excluded, pregnancy complications suggest an environmental insult to the developing testes.