Reduced fertility in women with X chromosome abnormality.

One patient with the karyotype 46,X,del(X)(p11.23) and three patients with 45,X/46,XX mosaicism were fertile or showed normal ovarian function. The patient with the Xp deletion has two daughters with the same chromosomal abnormality. A study of these patients and of others reported in the literature indicated that fertility of patients with X chromosomal abnormality has a markedly shorter duration than fertility of the normal female. Menopause commonly occurred during the second and third decade of age. We suggest that such fertility is related to the rate of germ cell attrition and hypothesize that germ cell attrition in the human female is influenced by genes of multiple effect which are carried on the X chromosome. The more of these genes which are present the slower the rate of germ cell attrition.