中国人群瘢痕疙瘩家系易感基因位点与染色体7p11的连锁分析

目的 探讨中国人群瘢痕疙瘩家系易感基因位点是否与7p11存在连锁关系。方法 从1个5代发病的中国人群瘢痕疙瘩大家系中选出32名具有较高遗传学研究意义的成员作为研究对象，采集他们的外周静脉血样，提取基因组DNA，参照国外最近相似研究的方法，在染色体7p11上选取已知的4个最大两点LOD值的微卫星为遗传标记。经PCR扩增，产物基因分型，再进行连锁分析。结果 在重组率0=0-4）．1时，这些微卫星标记的两点LOD值都小于-2．排除这些标记与染色体7p11的连锁关系。结论 首次发现了中国人群瘢痕疙瘩家系的易感基因位点不在染色体7p11上的遗传学证据，说明瘢痕疙瘩易感基因位点存在异质性。

Linkage analysis of keloid susceptibility loci on chromosome 7p11 in a Chinese pedigree

OBJECTIVE: To investigate whether the keloid susceptibility loci occur on chromosome 7p11 in a Chinese pedigree. METHODS: Peripheral venous blood samples from 32 members significant for hereditary investigation from a large Chinese keloid pedigree (with 5 affected generations) were collected for extracting genomic DNA. Four microsatellites on chromosome 7p11 with known maximal two-point LOD scores were selected as the genetic markers according to the method described in a recent report of the similar study. These markers were subsequently amplified by PCR, and all the PCR products were genotyped and linkage analyses were conducted. RESULTS: With the theta value of 0-0.1, the two-point LOD scores for these markers were all less than -2, which excluded the linkages of these markers to chromosome 7p11. CONCLUSION: This study provides the first genetic evidence that keloid susceptibility loci in Chinese pedigree do not locate on chromosome 7p11, suggesting the heterogeneity of familial keloid susceptibility loci.