A survey of sex chromatin abnormalities in mental hospitals.

Abstract

Sex chromatin surveys have shown that an addi- tional X chromosome is present in some or all of the cells of about 1 in 500 newborn males and of about 1 in 1000 newborn females, and that these anomalies may be 4-5 times commoner in inmates of mental deficiency institutions. The present survey was undertaken to determine the frequency of X chro- mosome abnormalities in patients with other mental disorders. It soon became obvious that the inci- dence was greater than that in the newborn population, and that it varied considerably from one hospital to another. The survey was, therefore, extended to embrace a population sufficiently large to eliminate gross sampling errors. Results were obtained in 6000 male and 6241 female in-patients of mental hospitals in Scotland, and in 966 female out- patients of a psychiatric clinic.