精神分裂症先证者家系早现遗传现象调查

A study of genetic anticipation in families of schizophrenic patients

目的：了解精神分裂症是否存在早现遗传现象。方法：对４５例精神分裂症家族史阳性的先证者进行家系调查，重点调查先证者和家系同病者的发病年龄和住院次数等。结果：从祖父母辈到父母辈再到先证者辈，平均发病年龄逐代提前，早现遗传现象家系符合率８７．９％。早现组先证者年平均住院次数０．５９次，是非早现组先证者年平均住院０．２０次的近三倍。早现组中高发家系占８．９％，比精神分裂症遗传流行学调查中高发家系占１．７％显著为高。结论：提示精神分裂症中至少有一亚型的遗传模式可能是单基因遗传，与不稳定ＤＮＡ有关。

Objective:To investigate whether genetic anticipation exists in schizophrenia. Method:Family charts were drawn up for 45 schizophrenic probands with positive family history.The age of onset and number of hospitalisation of the probands and the family members were recorded. Results:The average age of onset of illness decreased from the grandparents to probands generation.The family concordance rate of anticipation was 87 9%.The mean annual hospital admission rate for probands of the anticipation group was 0 59 while that of the non anticipation group was 0 2.The high risk families in the anticipation group made up 8 9% of the sample,much higher than the figure of 1 7% found in genetic epidemiology survey for schizophrenia. Conclusion:The study suggests that at least one subtype of schizophrenia may fit in to a single gene model,probably due to DNA instability.