Endocrine Abstracts

Introduction: We describe a case of 17- beta hydroxysteroid dehyrogenase Type III (17-βHSD3) deficiency in a girl from the travelling community. This case demonstrates how the clinical picture may not correlate with the biochemical results.

Case: A 4.7 year old girl presented for elective hernia repair. Intraoperatively, what was felt to be a testis was palpated. Investigations revealed a 46, XY karyotype. Pelvic ultrasound demonstrated absence of mullerian structures. Bilateral palpable gonads in the inguinal region with normal female external genitalia were found on clinical examination.

Family history was very difficult to obtain as parents were reluctant for disclosure of information. However, it was revealed that two maternal first cousins had presented with delayed puberty and required bilateral gonadectomies.

Initial impression was that of complete androgen insensitivity syndrome (CAIS) or a defect in testosterone biosynthesis. However, testosterone was undetectable with only a small increment in androstenedione post HCG stimulation. Androgen receptor (AR) sequencing revealed no mutations in the AR gene thus eliminating CAIS. Serum inhibin and anti-mullerian hormone (AMH) were detectable at 63 ng/l and 222 pmol/l respectively indicating the presence of functioning testicular tissue. A 24 h urine steroid profile was reported as normal with no evidence of an androgen biosynthesis defect. Further ongoing DNA analysis revealed no mutations in the SF1 or SRY genes but a positive mutation in intron 3 of the 17-βHSD3 gene.

Conclusion: Open communication is necessary for optimal investigation and management in 46, XY DSD individuals. However, confidentiality must be paramount. Ongoing research into molecular studies will allow for more precise diagnosis in these patients in the future. However, genetic testing is guided by the clinical and biochemical information. This case highlights the importance of continuously recalling the clinical picture despite conflicting biochemical results.