[Frequency of sex chromatin among mental patients].

The frequency of sex chromatin of 2000 cases of mental patients are observed in this paper. The frequency of Y chromatin in male and X chromatin in female was 28.01% and 26.86% respectively, whereas only 16.97% and 17.84% respectively in the control group. The mental patient group is higher than the control group significantly (P < 0.0001). It may be influenced by some psychotropic drugs and the factor of course. Positive X chromatin in the male patients was 8 cases and karyotypes of chromosome was XXY type all. The incidence of XXY type is 0.77% and significant higher than the control group (0.18%, P < 0.01). It suggested that ratio of add one X chromosome in the male mental patients be obviously increased. The authors indicated if this examination be routinely used in clinic that would prevent misdiagnosis and would raise accuracy of diagnosis.