家族性Ⅱ型糖尿病核心家系的遗传方式分析

Analysis on genetic pattern of familial type Ⅱ diabetes mellitus

目的 对 1992～ 1998年门诊及住院的家族性Ⅱ型糖尿病 (DM)患者 177个大家系及其中 2 14个核心家系的遗传方式进行研究 ,以探讨该病的遗传学特点。方法 采用家系分析、分离分析、多基因分析和阈值模式分析的方法 ,对家族性Ⅱ型DM大家系及核心家系进行研究。结果 177个大家系的Ⅱ型DM的遗传度为 143.0 6 %± 3 .3% ,提示在这些家系中有一个显性主基因存在。 2 14个核心家系中 ,U×U婚配型的子代分离比为 0 .470 3,U×A婚配型的分离比为 0 .483 8,A×A婚配型的分离比为 0 .6 712。多基因分析和分离分析显示 ,U×A家系不符合多基因遗传和常染色体隐性(AR)遗传 ,符合常染色体显性 (AD)遗传 ,U×U家系既不符合AD遗传 ,又不符合AR遗传。结论 家族性Ⅱ型DM的遗传方式表现遗传异质性 。

Objective To analyse hereditary familial type Ⅱ diabetes mellitus (type Ⅱ DM), including its pattern and the transmitted expression on different sex of type Ⅱ DM.Methods Familial analysis, segregation analysis, tests were used for multifactorial inheritance and threshold analysis. One hundred seventyseven pedigrees of familial type Ⅱ DM were studied.Results The heritability of familial type Ⅱ DM was 143.06 %± 3.3 %. One dominant major gene might influence the genesis of type Ⅱ DM. There were 214 nuclear families in 3 different mating types: U×U, U×A and A×A. The segregation ratios of U× U, U× A and A×A were 0.470 3 , 0.483 8 and 0.671 2 respectively. The results of tests for multifactorial inheritance and segregation analysis indicated that the genetic pattern of U×A and A×A nuclear families was not multifactorial inheritant and autosomal recessive (AR) but autosomal dominant (AD) inheritance. The genetic pattern of U×U nuclear families was neither AD nor AR inheritance. Conclusion There was genetic heterogeneity in type Ⅱ DM discovered with subgroupes of autosomal dominant inheritance in type Ⅱ DM.