目的对中国人X-连锁视网膜色素变性一家系进行分子遗传学检测,报告RPGR基因突变.方法首先对该家系X染色体进行致病基因的连锁分析,然后用单链构象多态性技术和直接DNA测序方法进行基因突变分析. 结果连锁分析在多态性微卫星遗传标记DXS8012和DXS8025产生正的Lod值分别为2.41(Zmax=2.40, θ=0) 和1.26.进一步单倍型分析确定该家系致病基因位于Xp21.1, 与 RP3连锁.用RPGR基因突变分析,在外显子ORF15+483_484发现GA缺失,引起阅读框架的改变,该基因缺失突变在家系中共分离.结论报告了中国人X-连锁视网膜色素变性RPGR基因外显子ORF15+483_484的GA缺失突变,丰富了中国人RPGR基因突变谱,为今后研究X-连锁视网膜色素变性的基因奠定基础.%Objective To report a novel mutation in RPGR gene in a Chinese family with X-linked dominant retinitis pigmentosa(XLRP). Methods Genetic linkage analysis was performed on the known genetic loci for XLRP with a panel of polymorphic markers, then the mutations were identified by single-strand conformation polymorphism(SSCP) and direct sequencing. Results Significant two-point Lod score was generated using marker DXS8025 (Zmax=2.4,θ=0). The disease gene locus was confined to Xp21.1 with further analysis of genetic linkage and haplotype. Mutations screening of RPGR gene in this family revealed a GA deletion at ORF15 +483_484 which caused the open reading frameshift. This novel mutation co-segregated with the affected members of the pedigree, but it was not present in the unaffected relatives. Conclusion The above finding expands the spectrum of RPGR mutations causing XLRP in Chinese family and is useful for further genetic consultation and genetic diagnosis.
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