Abstract
We report on two patients with 45,X/46,X,idic(Y) who showed different sex development. Case 1 is a 2-year-old boy. At one month of age his left retentio testis was noticed. Orchidopexy of left side was attempted when the patient was one year old, but gonadectomy was performed instead because an undifferentiated gonad was found. Pathological examination revealed ovotestis. Physical examination showed short stature (-2.6 SD), right testis (1 ml in volume), small penis (2.5 cm in length), and no signs of Turner syndrome. Chromosome analysis for peripheral lymphocytes revealed 45, X[5]/46, X, +mar[25].ish idic (Y) (q11.2) (SRY++, DYZ3++, DYZ1-). An HCG test showed a fairly good testosterone response (14→182 ng/dL). Case 2 is an 11- year-old girl. Physical examination showed short stature (-2.5 SD) and no signs of Turner syndrome. An LH-RH test showed excessive response (LH 36→400; FSH 200→480 mIU/mL). Small uterus was detected by abdominal echography. Because of the risk of gonadoblastoma, gonadectomy was performed. The bilateral gonads were streak gonads. Chromosome analysis of the resected gonad revealed 45, X[27]/46, X, idic (Y) (q12) [23]. PCR analysis of DNA from the resected gonad detected SRY. Since the rearranged Y chromosomes of both cases were positive for SRY, it is likely that the difference in the mosaic cell ratio in the gonad played an important role in their discordant sexual phenotypes.
