G6PD缺乏症基因型检测诊断与酶学诊断在应用中的比较分析

Comparative analysis of genotyping diagnosis and Enzymatic diagnosis for G6PD deficiency syndrome

目的比较分析葡萄糖-6-磷酸脱氢酶(G6PD)缺乏症利用基因型检测诊断与酶学诊断在临床中的应用效果。方法通过G6PD/6-磷酸葡萄糖酸脱氢酶(6PGD)比值法和多重SNa Pshot基因诊断技术对2014年6月至2015年9月进行常规检查的200例患者的静脉血标本进行G6PD缺乏症酶学诊断和基因型诊断,分析各自的检出情况。结果酶学诊断阳性率为4.5%。基因诊断突变率为22.0%,以c.[1311C>T(;)1365-13T>C]同义突变最常见(72.72%),错义突变率为5.35%。女性基因发生错义突变的比率明显低于男性,差异具有统计学意义(P<0.05)。另外,同性别的比较中,基因发生错义突变的几率明显低于另外两种突变类型,差异统计学意义(P<0.05)。多重SNa Pshot法基因分型结果均与DNA直接测序分析的结果完全一致。比值法无法检出同义突变,且漏检一例错义突变杂合子,其筛查错义突变的灵敏度和特异度分别是88.89%和100.00%。结论在G6PD缺乏症基因型检测中,G6PD/6PGD比值法虽可较有效地筛查错义突变但不能检出同义突变和全部的女性杂合子,而多重SNaPshot基因分型方法可有效检出多种G6PD基因突变类型。

Objective To compare the dectection result of glucose-6-phosphate dehydrogenase （G6PD） deficiency by enzymatic diagnosis and genetic diagnosis.Methods Both enzymatic diagnosis and genetic diagnosis were performed on 200 cases of blood samples by the G6PD/6-phosphogluconate dehydrogenase （6PGD） ratio test and the multiplex SNaPshot genetic diagnosis assay respectively.The typing results of G6PD/6PGD ratio test and multiplex SNaPshot assay were analyzed and compared.Furthermore, methodological evaluations of these two methods were performed based on the goldenstandard of sequencingresults.Results The positive rate of enzymatic diagnosis was 4.5%, while the mutation rate of genetic diagnosis was 22.0%.Synonymous mutation of c.[1311C〉T（;）1365-13T〉C] was the most common mutation （72.72%）.The rate of missense mutation was 5.0%.The G6PD/6PGD ratio of missense mutation specimens was significantly lower than that of synonymous mutation and of non-detected mutation （P〈0.05）.Whereas, there was no significant differences in the G6PD/ 6PGD ratio between synonymous mutation and non-detected mutation （P〉0.05）.All the genotyping results of multiplex SNaPshot assay were in complete concordance with the direct DNA sequencing.The ratio test cannot detect synonymous mutation.As one case of missense mutational heterozygote was not be detected by the ratio test, the sensitivity and specificity of this method for screening out missense mutation were 88.89% and 100.00% respectively.Conclusion Although G6PD/6PGD ratio test is a relative effective way of screening missense mutation, it could not detect synonymous mutation and all the female heterozygous carriers.Whereas, multiplex SNaPshot genotyping assay can detect various G6PD mutational types.