先天性智力低下儿童脆性X综合征的基因分析

目的探讨先天性智力低下与脆性X综合征智力低下基因1(Fragile X mental retardation gene 1,FMR-1)关系.方法应用复式PCR一次性扩增FMR-1基因的(CGG)n的重复区,检测CGG重复序列的大小,分析FMR-1基因状态:正常、前突变、全突变,对脆性X综合征可疑患儿进行快速筛查.结果在253例不明原因的先天性智力低下患儿中,检出脆性X综合征携带者(FMR-1基因前突变者)14例(2男12女),脆性X综合征患者(FMR-1基因全突变者)9例,阳性率达9.09%.结论脆性X综合征是引起儿童先天性智力低下的重要病因之一,应对不明原因的智力低下儿童进行大面积筛查,尤其是对有智力低下家族史的孕妇进行产前筛查,防止患儿出生.

Analysis of fragile X syndrome gene in congenital mental retard children

Objective: To discuss the relationship between the congenital mental retard and the FMR-1 (fragile X syndrome mental retardation gene 1). Method: The (CGG)n repeat sequences of FMR1 gene were amplified at one time by nest PCR and then determination of the sizes and the state of the gene: Normal, premutation and full mutation and screened out the suspicion affected quickly. Result: There were 14 FMR-1 gene carries (male 2 and female 12) and 9 affected cases in 253 congenital mental retard cases which were unknown the causes, the positive rate was 9.09%. Conclusions: The fragile X syndrome is one of the very important incidence for the children leading the congenital mental retard, we should screen those of unknown causes of congenital mental retard children at large range, especial for the pregnant women which have ever had a congenital mental retard family history preventing the next.