ESPE Abstracts (2016) 86 P-P2-389

Persistent Mullerian Duct Syndrome with Transverse Testicular Ectopia: A Novel AMH Receptor Mutation

Ozlem Korkmaza, Samim Ozena, Nurhan Ozcana, Petek Bayindirb, Sait Senc, Hüseyin Onayd, Damla Goksena, Ali Avanoglue, Ferda Özkinayd & Sukran Darcana

aDepartment of Pediatric Endocrinology, Ege University School of Medicine, Izmir, Turkey; bDepartment of Radiology, Ege University School of Medicine, Izmir, Turkey; cDepartment of Pathology, Ege University School of Medicine, Izmir, Turkey; dDepartment of Genetics, Ege University School of Medicine, Izmir, Turkey; eDepartment of Pediatric Surgery, Ege University School of Medicine, Izmir, Turkey

Background: Persistent Mullerian duct syndrome is the result of either anti-Mullerian hormone (AMH) deficiency or AMH receptor resistance. While the external genital structure is that of a normal virilized male, fallopian tubes and a uterus are observed in the internal genital structure. We present a case referred to our clinic because of female internal genital structure at laparoscopy during a surgical procedure performed due to undescended testes.

Objective and hypotheses: A long tubular structure (testis/?) was palpated during the physical examination of a 13-month-old male patient who admitted because of bilateral undescended testes. No testicular structure was found on the left scrotum and in inguinal canal and scrotum by ultrasonography. On the right, two structures thought to be testes, 12×8 mm and 11×7 mm in size, were determined proximally to the inguinal canal and in the middle section. The image was interpreted as transverse testicular ectopia on the right. Structures suggestive of ovaries, a uterus and fallopian tubes were observed during laparoscopic examination of the ectopic testis. Gonad biopsy was performed, and the patient was referred to the Pediatric Endocrinology Department for advanced investigation with a preliminary diagnosis of a disorder of sex development. First-degree consanguinity was present between the parents. In physical examination his weight was 10.2 kg (SDS: −1.06), height; 81 cm (SDS: −0.39) and BP was 98/60 mm/Hg. He was prader stage 5, the testes were impalpable and the phallus was 3.5 cm long. In the laboratory examination, karyotype was XY, SRY (+), FSH: 0.44 mIU/l, LH: 0.27 mIU/l, free testosterone: 0.3 pg/ml, total testosterone: 0.1 ng/dl, E2: <20 ng/ml, and AMH:>22 ng/ml. Immature seminiferous tubular structures were observed in gonad biopsy specimens. AMHR2 gene sequence analysis performed with a preliminary diagnosis of AMH receptor resistance revealed a previously unreported homozygous c.24G>A(p.W8X) mutation. The mother and father carried the same mutation in heterozygous form. The case was assessed as one of AMH receptor resistance. Orchiopexy was performed.

Conclusion: AMH receptor defect is a rare cause of 46 XY disorder of sex development. The condition should particularly be considered in virilized males with a normal external genital structure and persistent Mullerian structures.