[Studies on genetic model in familial type 2 diabetes mellitus]

This study is to explore the genetic model of type 2 diabetes mellitus (type 2 DM) among the hereditary family. One hundred and thirty-six pedigrees of familial type 2 DM were studied. The heritability of type 2 DM was estimated according to Falconer's method and the multi-factorial inheritance analyzed according to Penrose's method. Complex segregation analysis was performed using S.A.G.E-REGD. The heritability of familial type 2 DM was 94 07%-/+5.84%. Dominant major gene might influence the genesis of type 2 DM. Analysis of multi-factorial inheritance indicated that there be two genetic patterns respectively in male and female populations. By complex segregation analysis,environment,non-transmitted and co-dominant inheritance were rejected. Autosomal dominant (AD) inheritance and autosomal recessive (AR) inheritance was accepted but AR inheritance was the best pattern. This study suggested that type 2 DM had significant heritability and genetic heterogeneity,which appeared to be a disease of multi-factorial inheritance generally and autosomal dominant (AD) inheritance in part of pedigrees.