Long-term outcomes and molecular analysis of a large cohort of patients with 46,XY disorder of sex development due to partial gonadal dysgenesis.

BACKGROUND: Follow-up data on patients with 46,XY partial gonadal dysgenesis (PGD) until adulthood are scarce, making information on prognosis difficult. OBJECTIVE: To analyse the long-term outcomes of patients with 46,XY PGD regarding testosterone production, germ cell tumour risk, genotype and psychosexual adaptation. METHODS: A retrospective longitudinal study of 33 patients (20 assigned male and 13 patients assigned female at birth). Molecular diagnosis was performed by Sanger sequencing or by targeted massively parallel sequencing of 63 genes related to disorders of sex development (DSDs). RESULTS: Age at first and last visit ranged from 0.1 to 43 and from 17 to 53 years, respectively. Spontaneous puberty was observed in 57% of the patients. During follow-up, six of them had a gonadectomy (four due to female gender, and two because of a gonadal tumour). At last evaluation, five of six patients had adult male testosterone levels (median 16.7 nmol/L, range 15.3-21.7 nmol/L) and elevated LH and FSH levels. Germ cell tumours were found in two postpubertal patients (one with an abdominal gonad and one patient with Frasier syndrome). Molecular diagnosis was possible in 11 patients (33%). NR5A1 variants were the most prevalent molecular defects (n = 6), and four of five patients harbouring them developed spontaneous puberty. Gender change was observed in four patients, two from each sex assignment group; all patients reported satisfaction with their gender at final evaluation. Sexual intercourse was reported by 81% of both gender and 82% of them reported satisfaction with their sexual lives. CONCLUSION: Spontaneous puberty was observed in 57% of the patients with 46,XY PGD, being NR5A1 defects the most prevalent ones among all the patients and in those with spontaneous puberty. Gender change due to gender dysphoria was reported by 12% of the patients. All the patients reported satisfaction with their final gender, and most of them with their sexual life.

A Small Supernumerary Xp Marker Chromosome Including Genes NR0B1 and MAGEB Causing Partial Gonadal Dysgenesis and Gonadoblastoma.

Copy number variations of several genes involved in the process of gonadal determination have been identified as a cause of 46,XY differences of sex development. We report a non-syndromic 14-year-old female patient who was referred with primary amenorrhea, absence of breast development, and atypical genitalia. Her karyotype was 47,XY,+mar/46,XY, and FISH analysis revealed the X chromosome origin of the marker chromosome. Array-CGH data identified a pathogenic 2.0-Mb gain of an Xp21.2 segment containing NR0B1/DAX1 and a 1.9-Mb variant of unknown significance from the Xp11.21p11.1 region. This is the first report of a chromosomal microarray analysis to reveal the genetic content of a small supernumerary marker chromosome detected in a 47,XY,+der(X)/46,XY karyotype in a non-syndromic girl with partial gonadal dysgenesis and gonadoblastoma. Our findings indicate that the mosaic presence of the small supernumerary Xp marker, encompassing the NR0B1/DAX1 gene, may have been the main cause of dysgenetic testes development, although the role of MAGEB and other genes mapped to the Xp21 segment could not be completely ruled out.

Contribution of Clinical and Genetic Approaches for Diagnosing 209 Index Cases With 46,XY Differences of Sex Development.

CONTEXT: Massively parallel sequencing (MPS) technologies have emerged as a first-tier approach for diagnosing several pediatric genetic syndromes. However, MPS has not been systematically integrated into the diagnostic workflow along with clinical/biochemical data for diagnosing 46,XY differences of sex development (DSD). OBJECTIVE: To analyze the contribution of phenotypic classification either alone or in association with genetic evaluations, mainly MPS, for diagnosing a large cohort of 46,XY DSD patients. DESIGN/PATIENTS: 209 nonsyndromic 46,XY DSD index cases from a Brazilian DSD center were included. Patients were initially classified into 3 subgroups according to clinical and biochemical data: gonadal dysgenesis (GD), disorders of androgen secretion/action, and DSD of unknown etiology. Molecular genetic studies were performed by Sanger sequencing and/or MPS. RESULTS: Clinical/biochemical classification into either GD or disorders of hormone secretion/action was obtained in 68.4% of the index cases. Among these, a molecular diagnosis was obtained in 36% and 96.5%, respectively. For the remainder 31.6% classified as DSD of clinically unknown etiology, a molecular diagnosis was achieved in 31.8%. Overall, the molecular diagnosis was achieved in 59.3% of the cohort. The combination of clinical/biochemical and molecular approaches diagnosed 78.9% of the patients. Clinical/biochemical classification matched with the genetic diagnosis in all except 1 case. DHX37 and NR5A1 variants were the most frequent genetic causes among patients with GD and DSD of clinical unknown etiology, respectively. CONCLUSIONS: The combination of clinical/biochemical with genetic approaches significantly improved the diagnosis of 46,XY DSD. MPS potentially decreases the complexity of the diagnostic workup as a first-line approach for diagnosing 46,XY DSD.

A recurrent synonymous mutation in the human androgen receptor gene causing complete androgen insensitivity syndrome.

Androgen insensitivity syndrome (AIS) is the most common cause of 46,XY disorders of sex development (46,XY DSD). This syndrome is an X-linked inheritance disease and it is caused by mutations in the human androgen receptor (AR) gene. Non-synonymous point AR mutations are frequently described in this disease, including in the complete phenotype. We present a novel synonymous mutation in the human AR gene (c.1530C > T) in four 46,XY patients from two unrelated families associated with complete androgen insensitivity syndrome (CAIS). The analysis of mRNA from testis showed that synonymous AR mutation changed the natural exon 1 donor splice site, with deletion of the last 92 nucleotides of the AR exon 1 leading to a premature stop codon 12 positions ahead resulting in a truncate AR protein. Linkage analyses suggested a probable founder effect for this mutation. In conclusion, we described the first synonymous AR mutation associated with CAIS phenotype, reinforcing the disease-causing role of synonymous mutations.