Abnormal basal angle of the skull in sex chromosome aberrations.

The basal angle was measured on skull films in 252 patients with hormonal disorders and sex chromosome aberrations. In cases of hormonal disturbance the basal angle was normal. In patients with Turner's syndrome (45,X chromosomes) the basal angle was enlarged while in patients with Klinefelter's syndrome (47,XXY chromosomes) and in those with extra X or Y chromosomes it was definitely reduced. A close relationship exists between the sex chromosome number and the size of the basal angle.