Paternal Transmission of Maleness in XX Human Beings

Abstract

Phenotypic maleness was observed in a 7 1/2-year-old child and his father with an XY karyotype. Two brothers and a paternal uncle were found to have an XX sex-chromosome constitution. The boys' mother and sister were XX karyotype. Four of these five males had an extra small marker chromosome that did not appear to be involved in sex determination. Barr body counts of buccal smears and skin cells, drumstick counts, repeated lymphocyte and skin karyotypes, and quinacrine fluorescence studies of metaphase spreads, peripheral blood smears, and buccal smears were all consistent with the observed sex-chromosome findings. Except for the father's brother, who had partial testicular failure, the evaluated family members had appropriately normal serum concentrations of luteinizing and follicle-stimulating hormones, and total androgen. In addition, there appeared to be a preponderance of males in the father's sibship and among their offspring. Two separate male-determining loci seemed to be inherited in this family: the Y chromosome and a functioning autosomal locus.