常染色体显性遗传视网膜色素变性家系的基因筛查

目的：确定一个常染色体显性遗传视网膜色素变性(autosomal dominant retinitis pigmentosa,ADRP）家系的致病基因及其突变位点和类型。方法：应用聚合酶链反应－单链构象多态性结合DNA测序技术，对来自同一家系的4例RP患者及4名正常人外周血DNA进行分子遗传学分析，筛查3个候选基因共8个外显子。结果：来自同一家系的4例RP患者均发现有视紫红质基因（rhodopsin,RHO)第1外显子第52密码子存在TTC→TAC的点突变（Phe52Tyr），而4名正常人未发现这种突变。结论：在这个中国ADRP大家系中，发现RHO基因的致病突变，表明ADRP存在明显遗传异质性。

Screening of candidate genes in a family with autosomal dominant retinitis pigmentosa

OBJECTIVE: To determine the causative mutation in a 5 generation pedigree with autosomal dominant retinitis pigmentosa (ADRP). METHODS: Genomic DNA from four patients and 4 normal persons in the same pedigree suffering ADRP were extracted, and subsequently eight exons of three ADRP candidate genes were screened for mutations by a combined polymerase chain reaction-single strand conformation polymorphism and DNA sequencing techniques. RESULTS: A new point mutation in rhodopsin gene at codon 52 of exon 1 (TTC to TAC) that resulted in a substitution of Tyr to Phe was detected in the four affected family members, but not in the four control individuals from the same pedigree. CONCLUSION: A causative mutation of rhodopsin gene was identified in a large Chinese pedigree with ADRP. The present study confirmed the molecular genetic heterogeneity of ADRP.