Mongolism and maternal menarche.

Though the basic cause or causes responsible for the chromosomal aberration in mongolism are still obscure, it is generally agreed that the standard trisomic karyotype in this condition originates in the ovary. Measures of ovarian function could therefore be helpful in elucidating some of the factors involved. In this connexion, an opportunity arose to compare the stated age of onset of menstruation in mothers of mongols with that in an appropriate control group. The findings are reported, and briefly discussed, below.