Body size and shape in 46,XX males: an anthropometric investigation.

Anthropometric measurements of four 46,XX males are compared with those of their first degree male relatives, control males, and a sample of 47,XXY males. Most dimensions of 46,XX males are smaller than those of normal males. 46,XX males are also shorter and smaller than 47,XXY males. The present results support the earlier suggestion that there is a gene(s) in the Y chromosome with a general size-increasing effect and that the Y chromosome has an active role in the development of sex dimorphism in many body dimensions. These four 46,XX males may possess the Y chromosomal gene which sets the later timing of development in males.