RESUMO
Two unrelated phenotypically males with 46,XX karyotype are presented. The first patient is 5.5 year old who presented with congenital undescended testis while the other patient is 35 year old who has infertility since 6 years. Hormonal profile of the second patient is consistent with hypergonadotrophic hypogonadism with low testosterone level. The first patient's profile revealed a picture consistent with 21-hydroxylase deficiency. FISH technique using [Quint-Essential-Y-specific DNA probe] specific for Yp11.2 region was applied on metaphase spreads revealed the presence of Yp11.2 sequence on the short arm of the X chromosome in the second patient while it was absent in the first patient. DNA analysis of both patients using SRY gene amplification revealed the existence of SPY gene in the second patient and absence of the gene in the first patient. The possible underlying mechanisms for sex reverse in both cases are discussed