Sex-Chromosome Mosaicism of Type XYY/XO

Abstract

STUDIES of human chromosomes have been greatly facilitated by the development of newer technics, particularly peripheral blood leukocyte culture.^{1 2 3} Many abnormalities have been described, most of them involving altered numbers of chromosomes. These have been the subject of a number of recent reviews.^{4 , 5} Most of these abnormalities have been attributed to meiotic nondisjunction, with the production of abnormal gametes. However, a class of abnormalities has been found in which a defect occurring after fertilization must be postulated. These are cases of mosaicism, in which cells of differing karyotypes are found in the same person.Such chromosomal mosaicism was first described . . .