Detection of Molecular Variations at Androgen Receptor Gene in 46,XY Differences in Sex Development Cases.

Introduction: One of the common causes of 46,XY differences in sex development (DSD) cases is androgen insensitivity syndrome. This X-linked recessive inherited condition is associated with pathological variations of the AR gene, leading to defects in androgen action. Affected 46,XY infants or individuals experience variable degrees of undervirilization and those with severe form will have female-like external genitalia. Therefore, they were more likely assigned and reared as females. The confirmatory molecular test is often needed due to similar clinical manifestations with other conditions causing 46,XY DSD. Since in our country, the molecular test for the AR gene is lacking, the study is conducted as a preliminary study to elaborate on the possibility of developing a molecular test for the AR gene in 46,XY DSD cases. Methods: Archived DNAs of 13 46,XY DSD cases were analyzed using polymerase chain reaction and direct sequencing for molecular defects in the AR gene. Clinical and hormonal data were collected and analyzed. Results: The study successfully amplified and visualized the eight exons of the AR gene and revealed two subjects carrying AR gene variants at exon 7. In the first case, 1.2-year-old boy carried heterozygous p.Gln825Arg, which has never been reported elsewhere, and the second subject, a 2.1-year-old girl with heterozygous p.Arg841His. Both subjects presented with severe undervirilization of external genitalia with external genitalia masculinization scores (EMS) of 1.5 and 3. Conclusion: In this series, two of 13 46,XY DSD cases carried variants at the AR gene, resulting in complete androgen insensitivity syndrome.

Characterising SRD5A2 Gene Variants in 37 Indonesian Patients with 5-Alpha-Reductase Type 2 Deficiency.

The 5-alpha-reductase type 2 deficiency (5ARD2) is an autosomal recessive condition associated with impairment in the conversion of testosterone to dihydrotestosterone. This condition leads to undervirilisation in 46,XY individuals. To date, there have been more than 100 variations identified in the gene responsible for 5ARD2 development (steroid 5-alpha-reductase 2, SRD5A2). However, few studies have examined the molecular characterisation of Indonesian 5ARD2 cases. In the current study, we analysed 37 subjects diagnosed with 46,XY DSD (disorders of sex development) with confirmed variations in the SRD5A2 gene. We examined results from testosterone/dihydrotestosterone (T/DHT) and urinary etiocholanolone/androsterone (Et/An) ratios, as well as from molecular and clinical analyses. Twelve variants in the SRD5A2 gene were identified, and 6 of which were novel, namely, c.34-38delGinsCCAGC, p.Arg50His, p.Tyr136 ∗ , p.Gly191Arg, p.Phe194Ile, and p.Ile253Val variants. Moreover, we determined that 20 individuals contained harmful mutations, while the remaining 17 variants were benign. Those containing harmful mutations exhibited more severe phenotypes with median external genitalia masculinisation scores (EMS) of 3 (1.5-9) and were more likely to be diagnosed at a later age, reared as female, and virilised at pubertal age. In addition, the respective sensitivities for detecting severe 5ARD2 cases using T/DHT (cutoff: 10) and urinary Et/An ratios (cutoff: 0.95) were 85% and 90%, whereas mild cases were only identified with 64.7% and 47.1% sensitivity, respectively. Although we were unable to identify clear correlations between genotypic and phenotypic characteristics in this study, we clearly showed that individuals who were homozygous or compound heterozygous for any of the harmful mutations were more likely to exhibit classic 5ARD2 phenotypes, lower EMS, female assignment at birth, and virilisation during puberty. These results serve to inform the development of improved clinical and molecular 5ARD2 diagnostic approaches, specifically in Indonesian patients.