ESPE Abstracts

45,X/47,XYY mosaicism is quite rare, and, like 45,X/46,XY, it can be associated with mixed gonadal dysgenesis, Turner syndrome or apparently normal male/female phenotype. An infant aged 16 days, born full-term via spontaneous vaginal delivery to a 32 year-old G1P1 woman. His pregnancy and perinatal period were both uncomplicated except for maternal long QT syndrome. There was third degree cousin consanguinity between the parents. There was no any virilizing drug use and no maternal virilization during pregnancy. Physical examination was normal except for genital examination which revealed a 3.3 cm phallic structure, with an opening on its ventral side. The labia majora were posteriorly fused and rugated, and gonads were 1 ml and palpable bilaterally. His height was 56 cm, weight 4600 g, and head circumference 37 cm. His pulse rate was 120/min and blood pressure 80/50 mmHg. Laboratory examination showed normal gonadotropin levels consistent with mini-puberty as FSH: 3.9 mIU/ml (N, 1.37–13.5), LH: 6.2 mIU/ml (1.14–8.75) and total testosteron: 1.8 nmol/l. His serum adrenal androgens were in normal range (androstenedione: 25.9 ng/dL (normal, 5–45 ng/dl), 17-OH progesterone: 5.1 ng/ml (normal, <10 ng/ml)). There was no mullerian structure on pelvic ultrasonography. Chromosome analysis from peripheral blood cells revealed 45,X/47,XYY (80%–20%, respectively) karyotype. Fluorescence ın situ hybridization (FISH) revealed a similar karyotype as 45,X (77%)/47,XYY (223%) in 200 cell. Because of the 45,X/47,XYY karyotype, the patient was evaluated for Turner syndrome features and no any abnormalities could not be demonstrated. The patient was reared as male. In conclusion, karyotype analysis is an important diagnostic tool in DSD patients. A 45,X/47,XYY mosaicism should be kept in mind in DSD patients and needs a careful evaluation because of its phenotypic heterogenity.