XO/XY mosaicism with non fluorescent Y chromosome: clinical, cytogenetic and endocrinological studies on a female subject.

Cytogenetic, clinical and endocrinological studies were performed on a phenotypically female subject who had a XO/XY mosaicism. This patient had a primary amenorrhea. A disgenic testis on the left side and a primordial ovary on the right one was showed by laparotomy performed in this subject in the prepubertal age. The Y chromosome had not any fluorescence and was shorter than normal one. The basal plasma levels of various hormones and the hypothalamic-pituitary stimulation tests were similar to other subjects with gonadal disgenesis. However a low response of growth hormone to insulin tolerance test, showed in this case, suggest the necessity to early supply a sufficient replacement of therapy.