PCR analysis of Y-chromosome sequences in a 45,X male patient and a reviewof the literature

The 45,X karyotype is usually associated with Turner syndrome, while male p henotype is exceptional. The authors report a 45,X male patient with normal external genitalia and sex behavior, but who was azoospermic. He had a nor mally developed musculature and pilose distribution, testicular volume of 1 5 mt and no gynecomastia but clinical stigmata of Turner syndrome (short st ature, short neck and 4th metacarpal bones) and azoospermia. Hormonal plasm a levels of testosterone, estradiol, prolactin, and gonadotrophins were wit hin the normal range as was the response of luteinizing hormone (LH) and fo llicle-stimulating hormone (FSH) (30 and 60 min) after 100 mu g iv of LH-RH administration. Testicular biopsy could not be performed. Karyotype was 45 ,X without evidence of mosaicism. Polymerase chain reaction of genomic DNA studied with 12 different sequences of Y chromosome revealed only the prese nce of SRY gene (testis determining factor). It is possible that SRY/autoso mal translocation had occurred in this patient. The study of 45,X male shou ld be of great value in elucidating the complex mechanisms involved in norm al male sex differentiation.