常染色体隐性遗传家族性局灶节段性肾小球硬化的临床和遗传的异质性

Study on Clinical and Genetic Heterogeneity in Autosomal Recessive Familial Focal Segmental Glomerulosclerosis

目的研究常染色体隐性遗传(AR)家族性局灶节段性肾小球硬化(FFSGS)的临床和遗传异质性。方法1个中国皖北地区3代FFSGS家系(Han2005),采集本家系中27名成员的外周血样,选择位于1q25-31上的10个微卫星标记:D1S452、D1S242、D1S416、DIS466、D1S240、D1S254、D1S202、D1S222、D1S238和D1S413,应用PCR技术得到扩增产物片断,采用ABIPRISMTM310GeneticAnalyze测定PCR产物片段大小。利用Genescan(3.1版)、Genetyper(3.7版)软件处理后得到检测片段大小,依此得到每个样本的基因型。对基因型数据进行校对后,用连锁分析软件LINKAGE的MLINK程序计算每个标记的二点间LOD值,用LINK-MAP程序计算多点间LOD值,根据二点和多点间LOD值判断连锁关系。将Han2005与Martin等研究的FS-W家族进行相关比较。结果所有微卫星标记二点间LOD值在不同重组率时均<0,LOD值在重组率为0时均<-2,说明Han2005疾病基因与1q25-31区域无连锁关系,多点D1S416、D1S254、D1S202、D1S238和D1S413间LOD值也均<-2,进一步排除疾病基因位于1q25-31的D1S416至D1S413间19cM的区间内;把Han2005与FS-W家族比较后发现,2个家族存在临床和基因异质性。结论Han2005家系的疾病基因与已报道的FFSGS定位区域(1q25-31)无连锁关系;AR的FFSGS存在临床和遗传异质性,推测临床异质性与遗传异质性相关。

Objective To study the clinical and genetic heterogeneity in autosomal recessive of familial focal segmental glomerulosclerosis （FFSGS）. Methods A three - generation Chinese family with autosomal recessive FFSGS（ Hart2005 ） were investigated. The total number of the family members was 27 and they were given systemic physical examinations. Venous blood samples were taken for genetic analysis. DNA was extracted from peripheral blood using phenol -~ chloroform method. Ten microsatellite markers spanning the interest regions on chromosome lq25-31 were elected. These markers included D1S452, D1S242, D1S416, D1S466, D1S240, D1S254, D1S202, D1S222, D1S238 and D1S413. The DNA from each sample was amplified for the 10 markers. After polymerase chain reaction（ PCR）, PCR products of chromosome 1 with markers were subjected to electrophoresis. Then the length of the PCR products was judged with ABI PRISMTM 310 Genetic Analyzer. The data of PCR products were analyzed using the software Genescan version 3.1 and Genetyper version 3.7 （ Applied Biosystem, CA, USA）. After Mendelian checking, the eligible genotyping data were used for linkage analysis. Two - point linkage analysis was performed using the MLINK program version 5.1 ;muhipoint analysis was performed using LINK - MAP. Two families from Han2005 and FS - W were compared for clinical and genetic heterogeneity. Results The two - point log odds（LOD） scores were below zero and the maximum LOD scores at combination rate （0） = 0 were less than - 2 for all the markers. Thus, the linkage result showed no evidence that the disease locus was linked to any of these selected markers. Muhipoint linkage analysis of markers D1S416, D1S254, D1S202,D1 S238 and D1S413 conclusively excludes that pathogenic gene was linked to this region spanning approximately 19 cM on chromosome 1q25 - 31. There was clinical and genetic heterogeneity in 2 fami- lies by comparison. Conclusions There is no evidence that the Chinese family is linked to lq25 - 31 and there are differences between Han2005 and FS - W in clinical characteristics. Thus, the data demonstrate that there is clinical and genetic heterogeneity in autosomal recessive FFSGS. Clinical heterogeneity correlates likely with genetic heterogeneity.