海南省妇女儿童医学中心5246名女性新生儿葡萄糖-6-磷酸脱氢酶基因型与酶活性分析

Analysis of genotypes and enzymatic activities of G6PD in 5246 female newborns in Hainan Women and Children’s Medical Center

目的分析海南省妇女儿童医学中心女性新生儿葡萄糖-6-磷酸脱氢酶(G6PD)缺乏症的基因突变特点,探讨基因型与酶活性的关系。方法以2017—2019年在海南省妇女儿童医学中心新生儿疾病筛查中心完成G6PD初筛的女性新生儿血样本为研究对象,收集G6PD酶缺乏的干血斑样本2153份,同时为提高女性杂合子的检出率,随机抽取酶活性正常的干血斑样本3093份,共计5246份样本纳入研究。提取脱氧核糖核酸(DNA),采用多色探针荧光聚合酶链反应(PCR)熔解曲线法(MMCA法)检测G6PD基因突变。结果在5246份女性新生儿样本中共检出基因突变2801份,总检出率为53.39%(2801/5246),其中酶活性正常者占26.24%(735/2801)。发现13个突变位点的变异,有32种突变基因型,包括杂合突变型12种,纯合突变型6种和复合突变型14种。前7位最常见的突变位点依次是c.1376G>T、c.1388G>A、c.871G>A、c.95A>G、c.1024C>T、c.392G>T、c.519C>T,其中c.871G>A的检出率高于c.95A>G。同时发现1例罕见的突变位点c.593G>A。女性新生儿中复合突变和纯合突变与严重的G6PD缺乏症有关,它们的酶活性均明显低于单杂合突变的活性(P<0.001),而单杂合突变女性的G6PD活性分布非常广泛,无明显可分辨的界限值。结论海南省妇女儿童医学中心女性新生儿G6PD缺乏症的基因突变型复杂多样,热点突变是c.1376G>T、c.1388G>A、c.871G>A,其中c.871G>A具有海南地区的地域特性和女性特征。结合酶活性检测和MMCA法分析DNA,能有效提高女性G6PD缺乏症的检出率。该研究数据可为基因型和临床表型之间关系的研究以及群体遗传学的研究提供参考。

Objective To analyze the characteristics of gene mutations of glucose-6-phosphate dehydrogenase(G6PD)deficiency in female newborns in Hainan Women and Children’s Medical Center,and discuss the relationship between genotypes and enzyme activities.Methods Blood samples of female neonates who completed G6PD preliminary screening in Neonatal Disease Screening Center of Hainan Women and Children's Medical Center from 2017 to 2019 were selected as the research subjects.A total of 2153 samples of dried blood spots with G6PD enzyme deficiency were collected.At the same time,3093 samples of dried blood spots with normal enzyme activity were randomly selected to improve the detection rate of female heterozygotes.Totally 5246 samples were included in the study.Genomic DNA of the blood spots was extracted,and the G6PD mutation sites were detected by multicolor melting curve analysis(MMCA)of PCR.Results A total of 2801 gene mutations were detected in 5246 samples of female neonates,the detectionrate being 53.39(2801/5246),of which the normal enzyme actiuity accounted for 26.24%(735/2801).Thirteen mutations sites were detected and 32 genotypes were found,including 12 heterozygous mutations,6 homozygous mutations and 14 compound mutations.The top seven mutation sites were c.1376G>T,c.1388G>A,c.871G>A,c.95A>G,c.1024C>T,c.392G>T,c.519C>T,and the detection rate of c.871G>A was higher than that of c.95A>G.In addition,a rare mutation site of c.593G>A was found.Homozygous mutation and compound mutation were associated with severe G6PD defciency,the enzyme activities of them were obviously lower than those of heterozygous mutation,while G6PD activity of heterozygous mutations were widely distributed,and there was no obvious distinguishable limit value of heterozygous mutations.Conclusion The gene mutation types of G6PD deficiency in female newborns of Hainan Women and Children’s Medical Center are complex and diverse,and the hot spot mutations are c.1376G>T,c.1388G>A,c.871G>A.The mutation site of c.871G>A has the specific regional and female characteristics of Hainan.Combining enzyme activity detection with MMCA analysis of DNA can effectively improve the detection rate of G6PD deficiency in female newborns.This research data can provide reference materials for the study of the relationship between genotype and clinical phenotype,and the study of population genetics.