Abstract 33: Clinical exome sequencing in XY DSD

Background: XY DSD presents as a diagnostic dilemma, making genetic tests essential for diagnosis. Aims and Objectives: Determine diagnostic yield of clinical exome sequencing in XY DSD patients &Ascertain concordance between clinical diagnosis and genetic diagnosis in case of XY DSD. Results: 39 patients were included in this observational study. Mean age at presentation was 7.5 years. Consanguinity was present in 23 cases (59%) and 24 (61.5%) were reared as males. The median External Masculinization Score was 3/12. Commonest clinical/biochemical and genetic diagnosis was partial androgen insensitivity syndrome in 17 Patients (43.6%) and 5 patients (22.7%) respectively. Clinical Exome detected mutation in 22 cases (56.4%). In 10 cases (45.45%) the variant was pathogenic. 4 (18%) cases showed a likely pathogenic variant and 8 cases (36%) showed variant of unknown significance. Discordance between clinical and genetic diagnoses was seen in 6 (27.27%) of cases. In 17 (43.6%) cases, we failed to detect any genetic abnormalities. Conclusion: Although clinical exome sequencing picked up 56.4% of cases, it led to change in diagnosis in 27.27% cases which potentially could alter management and improve clinical outcomes. However clinical exome failed to detect mutations in significant proportion of patients.