深圳市龙华区地中海贫血基因分型情况分析

Analysis on the Genotyping of Thalassemia in Longhua District,Shenzhen

目的了解深圳市龙华区地中海贫血基因突变类型及分布状况,为该地区优生优育提供参考和指导。方法收集2017年1月~2019年12月到深圳市龙华区人民医院进行地中海贫血筛查人群12898例,通过检测血常规,对红细胞平均体积(MCV)<80 fl和/或红细胞平均血红蛋白含量(MCH)<27 pg的标本通过血红蛋白电泳进行地中海贫血的初筛,初筛表型阳性者则进一步行地中海贫血基因诊断,分析基因诊断结果。结果12,898例地中海贫血初筛阳性受检者3126例,阳性率为24.23%;基因诊断为地中海贫血905例,检出率为7.02%;α-地中海贫血547例,检出率为4.24%,常见缺失类型基因型为--SEA/αα、-α3.7/αα、-α4.2/αα、分别占64.53%、20.48%、8.23%,--SEA/αα基因阳性率高于其它基因突变型,不同基因缺失型构成比较,差异有统计学意义(P<0.05);β地中海贫血基因突变324例,检出率为2.51%,共检出13种基因型,均为杂合子,其常见突变类型基因型为CD41-42、IVS-Ⅱ-654、-28,分别占35.49%、24.69%、15.12%,CD41-42基因突变检出率高于其它基因突变型,不同基因突变类型检出率比较,差异有统计学意义(P<0.05);α、β复合型地中海贫血34例。结论深圳市龙华区地中海贫血有一定的发病率,基因突变类型十分复杂,东南亚缺失型(--SEA/αα)是α-地中海贫血基因型中最为常见,而β-地中海贫血中,以CD41-42突变和IVS-Ⅱ-654突变最为常见,该地区α、β地中海贫基因型构成排序基本符合广东省地中海贫血基因分布特点,应对该地区育龄人群开展地中海贫血相关知识宣传、加强孕前筛查以及产前诊断,促进优生优育。

Objective To understand the types and distribution of thalassemia gene mutations in Longhua District,Shenzhen,and provide reference and guidance for prenatal and postnatal care in this area.Methods A total of 12,898 patients who went to Shenzhen Longhua District People’s Hospital for thalassemia screening from January 2017 to December 2019 were collected.Through blood routine testing,the specimens with mean red blood cell volume(MCV)<80 fl and/or mean red blood cell hemoglobin content(MCH)<27 pg were screened for thalassemia by hemoglobin electrophoresis.Those with a positive phenotype in the initial screening will be further diagnosed with thalassemia and the results of the genetic diagnosis will be analyzed.Results 12,898 cases of thalassemia were screened positive for 3126 cases,the positive rate was 24.23%;905 cases of thalassemia were genetically diagnosed,and the detection rate was 7.02%;There were 547 cases ofα-thalassemia,the detection rate was 4.24%,and the common deletion genotypes were--SEA/αα,-α3.7/αα,-α4.2/αα,which accounted for 64.53%,20.48%,and 8.23%,respectively,--SEA/ααgene positive rate was higher than that of other gene mutation types,and the difference in composition of different gene deletion types was statistically significant(P<0.05);There were 324 cases ofβ-thalassemia gene mutations,with a detection rate of 2.51%.A total of 13 genotypes were detected,all of which were heterozygous.The common mutation types were CD41-42,IVS-Ⅱ-654,-28,which accounted for 35.49%,24.69%,and 15.12%respectively.The detection rate of CD41-42 gene mutation was higher than that of other gene mutation types and different gene mutation types.Compared with the detection rate,the difference was statistically significant(P<0.05);There were 34 cases ofαandβcomplex thalassemia.Conclusion There is a certain incidence of thalassemia in Longhua District,Shenzhen,and the types of gene mutations are very complicated.The Southeast Asian deletion type(--SEA/αα)is the most commonα-thalassemia genotype.Amongβ-thalassemias,CD41-42 mutations and IVS-Ⅱ-654 mutations are the most common.The order ofαandβ-thalassemia genotypes in this area is basically in line with the characteristics of thalassemia gene distribution in Guangdong Province.The population of childbearing age in this area should carry out the promotion of thalassemia-related knowledge,strengthen pre-pregnancy screening and prenatal diagnosis,and promote prenatal and postnatal care.