[XX-male-syndrome. Pathogenesis and aspects of diagnostic pitfalls (author's transl)].

A boy with XX-karyotype displayed classical features of Klinefelter's syndrome. In the nuclei of hair root cells Barr-bodies were present as well as brightly fluorescent (F-)bodies resembling closely a Y-body. In lymphocyte metaphases, however, this F-body of the interphase nuclei corresponded to a brightly fluorescent segment of the short arm of a D15-chromosome was found in the father's karyotype. This case does not give convincing support to any of the theories suggested in the etiology of the XX-male phenomenon.