导致人视网膜色素变性的RPGR基因突变

Mutations in the RPGR Gene Responsible for Retinitis Pigmentosa

用PCR－SSCP和DNA测序的方法在两个XLRP家系RPGR基因的12号和9号外显子内各发现一个未报道的突变．12号外显子内的单碱基缺失引起mRNA翻译时阅读框移位，翻译提前终止，产生的多肽片段含499个氨基酸残基，且其C末端6个残基异常；9号外显子内的无义突变导致产生只含331个氨基酸残基的多肽．这两个突变引起了严重的视网膜色素变性．

Mutants were screened by PCR-SSCP and DNA sequencing in two XLRP pedigrees. Two novel mutation sites were identified in exon 12 and 9 of RPGR gene respectively.A 1-bp deletion in exon 12 caused a premature arrest after 499 amino acids due to a frameshift change, resulting in a truncated protein with six abnormal C-terminal amino acids. A nonsense mutation in exon 9 changed codon 333 to a terminal one and resulted in a truncated protein of only 332 residues. The two mutations caused severe retinitis pigmentosa in the families.