Abstract 105: A rare case of 46XX testicular disorder of Sex developement

Background: 46 XX testicular disorder of sex development (DSD) is rare disorder with incidence of 1;20,000 in new-born males. Majority of cases occur due tothe translocation of the sex-determining region of the Y chromosome (SRY) to X chromosome. Presentation is usually in adolescence or adulthood when they present with poor development of secondary sexual characters or with infertility. We have presented a case of 46 XX male and discussed the management. Case presentation: A 20-year-old male presented to us with complaints of poor development of secondary sexual characteristics. He was born with unambiguous male genitalia and was assigned male sex of rearing. He identified himself as He and assumed a male gender role. He attained puberty at 16 years of age. On examination, he was short in height (below 3rd centile for his age and sex) and underweight. He had absent facial hair, sparse axillary hair, and no gynecomastia. Genital examination showed virilization with pubic hair tanner stage 4, stretched penile length normal as per age, with completely fused and well-developed scrotumbut small-sized testicles (3cc bilateral). On hormonal investigation, he was found to have hypergonadotropic hypogonadism. Usual causes of hypergonadotropic hypogonadism like Klinefelter's syndrome, and local infective, infiltrative or benign causes like varicocelewere suspected. Ultrasound of the scrotum was normal ruling out local causes. Karyotype showedthe presence of XX sex chromosome and Fluorescent in situ hybridization studies showed SRY gene translocation to the short arm of chromosome X – leading to 46XX sex reversal. Patient was started on testosterone replacement and considering the risk of gonadoblastoma; a bilateral orchidectomy was done. Poor fertility prospects were explained. Conclusion: This case describes a rare case of 46 XX DSD with sex reversal due to SRY gene translocation. SRY is a sex-determining gene present on Y chromosome and its presence causes bipotential gonads to develop into testis. 46 XX DSD should be considered a differential in any patient presenting with small testicular size and poor secondary sexual characteristics.