一个视网膜色素变性家系的基因诊断和产前诊断

Genetic and prenatal diagnosis of a retinitis pigmentosa pedigree

目的寻找一个视网膜色素变性家系的致病基因突变，并对该家系进行产前基因诊断。方法运用高通量测序对该家系的先证者173个遗传性眼病相关基因的序列进行检测，用Sanger测序法对高通量测序的结果进行验证，并对家系的其他患者与携带者进行致病基因突变的检测。结果 先证者存在X染色体连锁、与视网膜色素变性相关的RP2基因第2外显子c.570_571 ins GAAGATGCTGT插入突变，家系中的女性携带者均有该致病基因的杂合突变，男性患者均携带有该致病基因的半合子突变。结论该家系视网膜色素变性的遗传方式为X-染色体连锁隐性遗传，RP2基因第2外显子的c.570_571 ins GAAGATGCTGT插入突变可能为该家系视网膜色素变性的致病突变，可以根据该突变对家系中的携带者进行产前基因诊断。

Objective To explore the genetic etiology of a pedigree affected with hereditary retinitis pigmentosa. Methods High-throughput DNA sequencing was used to analyze the sequences of 173 genes associated with hereditary eye diseases in the proband. Suspected mutation was verified with PCR amplification and Sanger sequencing. Results The proband was found to have carried a c. 570_571 ins GAAGATGCTGT insertional mutation in the RP2 gene located on the X chromosome. All female carriers of the pedigree were heterozygous, while all affected males were hemizygous for the same mutation. Conclusion The inheritance pattern of this retinitis pigmentosa pedigree was X-linked recessive. The c. 570_571 ins GAAGATGCTGT insertional mutation of the RP2 gene probably underlies the disease.