[A comparative study on 8 high and low density families of schizophrenia]

The writers select 8 families with high density of schizophrenia from Wuhan local data of psychiatric epidemiology. Among first degree relative of each family there are 3 or more than 3 sufferers. The selection is compared with 8 low density families of schizophrenia chosen by random. The comparison indicates that the total suffering ratio in high density families and their 1st. 2nd and 3rd degree relatives suffering ratio differ notably from the total suffering ratio of the low density families and their corresponding relatives (P < 0.01, respectively). There is also marked difference on the full brother or sister suffering ratio. The ratio of consanguineous marriage, course of illness and prognosis are also different between the high density family group and the low group. The result suggests that the high density group has high heredity- ability. But it is hard to explain the genetic mode through general analytic method. The writers agree with Mr Jiang sanduo's opinion that schizophrenic is a polygenic disease with a major dominant gene.