应用微卫星多态位点对X连锁型视网膜色素变性疾病进行遗传连锁分析的研究

目的应用遗传连锁分析方法对X连锁型视网膜色素变性家系进行分析，确定其致病基因的所在位点。方法在2个目前常见的X-连锁遗传位点——RP2和RP3处分别选取具有高信息量的微卫星位标，对2例疑似X连锁型视网膜色素变性家系进行遗传连锁分析。通过对家系成员的单倍型分析，并使用两点法计算其最大优势时数（LOD Score）值，确定致病基因所在的染色体位置。结果微卫星标记DXS993与2例遗传家系表型间最大LOD值分别为：〈-2和0．8；DXS 1068在2例遗传家系LOD值分别为0．4和0．8。结论RP2基因可能不是XY家系的致病性基因；在ZLK家系，怀疑疾病位点与RP2或RP3基因连锁。用遗传连锁分析方法确定致病基因所在染色体的范围起到重要的作用。

Investigation on genetic linkage analysis of X-linked retinitis pigmentosa using microsatellite markers

Objective To identify the disease locus in X-linked retinitis pigmentosa(XLRP) families using genetic linkage analysis.Methods Two microsatellite markers were selected from the RP2 and RP3 gene loci,haplotype analysis for two XLRP families was performed respectively to determine the critical region.Two-point linkage analysis was performed using MLINK program.Results The Lod scores of DXS 993 markers vs XLRP were below -2 and 0.8;and DXS 1068 makers were 0.4 and 0.8.Conclusion The phenotype of XY family is not caused by mutation of RP2 gene and ZLK family may be linked to RP2 or RP3 gene.Genetic linkage analysis for XLRP families is useful.