Y-chromatin positive cells in the smear preparations of the gonad from a XX male.

An ambisexual male infant showed a normal female karyotype by the leukocyte culture technique in two different occasions. Cultured fibroblasts from the right gonad had also a 46, XX complement. They were Y-chromatin negative. To our surprise, Y-chromatin was observed in 96% of the nuclei in smears from the uncultured gonad. It is emphasized that the examination of the uncultured gonad by the quinacrine technique is mandatory in the study of "XX males".