X-连锁迟发性脊椎骨骺发育不良家系SEDL基因突变及基因诊断  

Idenfification of a missense mutation in SEDL gene from a Chinese family with X-linked spondyloepiphyseal dysplasia tarda

作　　者：周万军[1] 周世媛 黄盛文[1] 周继苹 徐湘民[1] 

机构地区：[1]南方医科大学医学遗传学教研室,广州510515 [2]河南省人口与计划生育科学技术研究院

出　　处：《中华医学遗传学杂志》2008年第1期15-18,共4页Chinese Journal of Medical Genetics

摘　　要：目的确定一个X-连锁迟发性脊椎骨骺发育不良 （X-linked pondyloepiphyseal dysplasia tarda,SEDL）家系的基因突变类型；建立一种快速基因诊断方法。方法采用体格检查、影像学检查及家系分析进行临床诊断。针对SEDL基因的第3～6外显子及其侧翼序列设计4对引物，建立基于PCR的变性高效液相色谱技术（denaturing high performance liquid chromatography, DHPLC）快速基因分型方法。常规酚-氯仿法从该家系3代18名成员的外周血中提取基因组DNA，经PCR／DHPLC分析，筛查出SEDL基因突变所在的片段，对该片段进行序列分析以确定突变位点及类型。结果DHPLC分析发现该家系的SEDL基因突变位点在第4外显子片段，序列分析证实为c．218C〉T突变，导致氨基酸序列S73L改变。在该家系的18名成员中，3例男性患者，5例女性肯定携带者和2例未婚女性携带者均带有该突变，其余表型正常的8名成员中未检测到这一突变。各成员的DHPLC峰型所代表的基因型与表型结果相吻合。结论首次报告中国人SEDL基因c．218C〉T突变，丰富了中国人SEDL基因的突变谱。采用的技术快速、可靠，能对SEDL进行快速基因分型和产前诊断。Objective To identify the SEDL gene mutation in a Chinese family with X-linked spondyloepiphyseal dysplasia tarda （SEDL） and to establish a genotyping assay for rapid diagnosis of this X-linked recessive disorder. Methods Clinical diagnoses were made based on physical examination, radiological examination and pedigree analysis for this family. Four primer pairs flanking the SEDL exons 3-6 including their exon/intron boundaries were designed. A rapid genotyping assay based on denaturing high performance liquid chromatography （DHPLC） was established to screen the point mutations of the SEDL gene. Genomic DNA was extracted by standard methods from 18 members in the three generations of the pedigree and subjected to PCR-denaturing high performance liquid chromatography （PCRDHPLC） assay followed by direct DNA sequencing. Results A c. 218C 〉 T mutation in exon 4 of the SEDL gene, which resulted in a substitution of serine 218 with leucine, was identified in this family. Among the 18 members, 3 patients, 5 obligate female carriers and 2 unmarried young females were found to have the missense mutation, and other 8 healthy individuals were not detected to carry the mutation, in which genotype-phenotype correlations were well established in each member investigated in this family. Conclusion A c. 218 C 〉 T missense mutation in the SEDL gene was firstly reported in Chinese population and the results of this study expand the spectrum of SEDL mutations. The PCR-DHPLC assay is a useful tool to rapidly detect the SEDL mutation in clinical and prenatal diagnosis.

关 键 词：X-连锁迟发性脊椎骨骺发育不良 X-连锁迟发性脊椎骨骺发育不良 变性高效液相色谱 基因突变 

分 类 号：R681.1[医药卫生—骨科学]