Novel high-throughput SNP genotypling cosegregation analysis for genetic diagnosis of autosomal recessive retinitis pigmentosa and Leber congenital amaurosis
Novel high-throughput SNP genotypling cosegregation analysis for genetic diagnosis of autosomal recessive retinitis pigmentosa and Leber congenital amaurosis
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DOI：
10.1002/humu.20479
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发表时间：
2007-05-01
期刊：
影响因子：
3.9
通讯作者：
Gonzalez-Duarte, Roser
中科院分区：
文献类型：
--
作者：
Pomares, Esther;Marfany, Gemma;Gonzalez-Duarte, Roser
色素性视网膜炎（RP）是成人失明的主要原因，是一种异质性很强的单基因疾病。目前已鉴定出32个以上的致病基因，其中18个与常染色体隐性RP （arRP）有关；然而，超过50%的病例仍未分配。没有发现arRP的主要致病基因，也没有发现任何普遍的突变，这使得已经报道的RP基因的突变筛选非常耗时和昂贵。尽管如此，这一步骤对于患者和潜在携带者的遗传诊断是不可避免的，也是接近新的RP基因和位点鉴定的先决条件。我们设计了一种创新的高通量、高成本效益的策略，通过SNP基因分型对arRP和Leber先天性黑内障（LCA，一种常染色体隐性视网膜营养不良，具有一些RP基因和特征）的22个基因进行共分离分析。这种新的间接方法已在54个近亲和非近亲arRP家族中得到验证。在一个简单而快速的基因分型步骤中：1)我们在13%的家系中丢弃了所有22个候选基因，突出了选择的家庭，以寻找新的arRP基因/位点；2)我们平均排除了每个家族18-19个基因，从而减少了筛选致病突变的基因数量；3)我们在一个家族中发现了CERKL是RP的致病基因，而这个候选基因之前被微卫星共分离分析所抛弃。这种方法也可以应用于其他具有高遗传异质性的非视网膜疾病，如遗传性耳聋或帕金森病。
Retinitis pigmentosa (RP), the major cause of blindness in adults, is an extremely heterogeneous monogenic disorder. More than 32 causative genes have been identified, 18 of which are involved in autosomal recessive RP (arRP); however, more than 50% of the cases remain unassigned. There are no major causative genes identified for arRP nor any prevalent mutations, which make mutational screening of the already reported RP genes extremely time consuming and costly. Nonetheless, this step is unavoidable for genetic diagnosis of patients and potential carriers, and it is a prerequisite before approaching the identification of new RP genes and loci. We have designed an innovative high throughput time- and cost-effective strategy for cosegregation analysis of 22 genes of arRP and Leber congenital amaurosis (LCA; an autosomal recessive retinal dystrophy that shares some of the RP genes and traits) by SNP genotyping. This novel indirect method has been validated in a panel of 54 consanguineous and nonconsanguineous arRP families. In a single and fast genotyping step: 1) we discarded all the 22 candidate genes in 13% of the pedigrees, highlighting the families of choice to search for novel arRP genes/loci; 2) we excluded an average of 18-19 genes per family, thus diminishing the number of genes to screen for pathogenic mutations; and 3) we identified CERKL as the causative RP gene in a family in which this candidate had been previously discarded by microsatellite cosegregation analysis. This type of approach can also be applied to other nonretinal diseases with high genetic heterogeneity, such as hereditary deafness or Parkinson disease.