ESPE Abstracts

Context: The 45,X/46,XY mosaicism poses a great clinical challenge influencing gonadal development, histology, hormonal balance, and growth. Patients present a wide spectrum of phenotypes with varying degrees of genital ambiguity from Turner Syndrome to male. Here, we present five children with 45,X/46,XY mosaicism presenting with different clinical phenotypes.

Case Descriptions:

Case 1: An 11 years-old girl was presented with short stature and typical female genitalia. Initial clinical diagnosis was Turner Syndrome with short stature, high gonadotropin concentrations and small uterus, undetectable ovaries on pelvic ultrasonography. After karyotype analysis, gonadectomy was performed and the histological examination revealed bilateral streak gonads.

Case 2: A 2 days-old neonate was presented with asymmetric genital appearance. In physical examination, the left gonad was in the scrotum and the right gonad was unpalpable. The karyotype confirmed 45,X/46,XY mosaicism. The right streak gonad, right side of the uterus and tuba were present, in the laparoscopy. Histological examination revealed testis in the left gonad. The patient was raised as a male and was followed at 3-6 months` intervals for malignancy risk. Growth hormone treatment was started at the age of seven, when the growth rate decreased.

Case 3: A 14 years-old boy was presented with short stature. His height was 146 cm (-2.8 SDS), target height was 178.5 cm (0.37 SDS). At the presentation, testes were 15/8 cc, palpable in the scrotum, penile size was 5x1 cm and there was no hypospadias. After karyotype confirmed 45,X/46,XY mosaicism, testicular biopsy was planned but the parents refused.

Case 4: A 18 months-old girl was presented with isolated clitoromegaly. Uterus and ovaries were visualized on pelvic ultrasonography. After karyotype confirmed 45,X/46,XY mosaicism, laparoscopic gonadectomy was performed. Histological examination revealed an ovotesticular gonadal phenotype: ovarian stroma in the left gonad and testis in the right gonad. Growth hormone treatment was started at the age of three, when the growth rate decreased.

Case 5: A 15 years-old boy was presented with gender dysphoria. He had typical male genitalia and normal hormonal tests. There were no erection and ejaculation problems. The karyotype confirmed 45,X/46,XY mosaicism, the patient refused testicular biopsy.

Conclusion: 45,X/46,XY mosaicism is associated with variable clinical phenotypes irrespective of degree of mosaicism in blood. Short stature is an important problem in all phenotypes for which GH therapy is indicated. In cases without band/dysgenetic gonads in laparoscopy, the decision for prophylactic gonadectomy should be considered according to the histopathological assessment.