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.