广西崇左市中学生地中海贫血流行病学调查及基因突变类型分析

目的 对广西崇左市中学生进行地中海贫血(地贫)流行病学调查,了解地贫基因携带率和地贫基因突变类型.方法 2008年6月10-20口在崇左市所辖7个区县(市)中抽签分别确定一所中学,在志愿参加调查的学生中按当地人口0.5‰比例确定调查人数,检测12～16岁学生1097名(男515名,女582名),其中壮族968名(男438名,女530名),汉族128名(男76名,女52名),瑶族1名(男性).以Cell Dyn 1700全自动血细胞分析仪进行血细胞分析,以血红蛋白自动分析仪--VARIANT进行血红蛋白F和血红蛋白A2(HbA2)定量检测.HbA2≥4%为β地贫另进行α和β地贫基因分析,HbA2≤4%但平均红细胞体积(MCV)≤80 fl的标本进行a地贫基因分析.结果 1097名学生中地贫总检出率为25.62%.其中检出α地贫218例(19.87%),β地贫50例(4.56%),α地贫复合β地贫13例(1.19%).男生检出地贫133例(25.83%),女生检出地贫148例(25.43%),男女生间检出率差异无统计学意义(P>0.05).968名壮族学生检出地贫255例(26.34%),128名汉族学生检出地贫25例(19.52%),壮族学生检出率高于汉族学生,差异有统计学意义(P<0.01).检出3种缺失型α地贫基因(-α3.7/,-α<4.2/和--SEA/)和3种非缺失型α地贫基因(ααCS/、ααWS/和ααQS/),其中ααWS/检出率较高.β地贫基因突变类型以CD41-42最为常见.地贫MCV低于健康对照,差异有统计学意义(P<0.01).在MCV为79～80fl的样本中检出α地贫,如果以MCV<79 fl为地贫表型阳性的指标,则有32例漏诊,漏诊率达2.97%.结论 广西崇左市中学生地贫基因携带率高,壮族学生检出率高于汉族学生;ααWS/检出率较高,β地贫基因突变类型以CD41-42最为常见.

Epidemiological investigation and genotype of thalassemia on middle school students in Chongzuo, Guangxi

Objective To investigate the carrier ratio and the genotype of thalassemia among students of secondary school in Chongzuo, Guangxi. Methods From June 10-20,2008 among 7 regions of Chongzuo, 1 secondary school was randomly chosen from each region, and the number of student volunteers was determined by 0.5‰ proportion of the local population size. 1097 students were screened, including 515 boys and 582 girls of 12-16 year olds. Among them, 968 cases were Zhuang (438 boys and 530 girls) 128 cases were Han (76 boys and 52 girls) and one case was Yao nationalities (boy). Analysis of blood cells was detected by Cell Dyn 1700 automatic hemocyte analysator while hemoglobin F (HbF) and hemoglobin A2 (HbA2) were detected by hemoglobin autoanalyse variant. Among those with HbA2≥ 4% that belonged to β-thalassemia before α and β-thalassemia gene were analyzed to identify the genotypes. IfHbA2 was <4% but MCV≤80 fl, α-thalassemia gene was analyzed. Results Among 1097 cases,218 wereα-thalassemia (19.87%), 50 were β-thalassemia (4.56%) and 13 were combination of α β-thalassemia (1.19%). The overall detected ratio was 25.62%. 133 cases with thalassemia were boys (25.83%) and 148 were girls (25.43%) with no significant difference(P>0.05). 255 cases of thalassemia were Zhuang (26.34%), and 25 were Han nationality (19.52%). The detected ratio among Zhuang nationality was higher than in Hun nationality and with significant difference statistically (P<0.01). 3 kinds of deletion (-α3.7/,-α<4.2>/, --SEA/) and another 3 kinds of non-deletion (αα CS/, αα WS/, αα QS/) α-thalassemia genotype were identified, with a higher rate of ααWS/. Among the β-thalassemia genotype, CD41-42 appeared the most common genotype. MCV of thalassemia was lower than in the controls, with significant difference (P<0.01). 78-90 fl of α-thalassemia was detected from the MCV specimen. If taken MCV<79 fl as the positive phenotype of thalassemia, 32 cases were misdiagnosed. The rate of missed diagnosed cases was 2.97%. Conclusion Rate of thalassemia carder among students of secondary school in Chongzuo, Guangxi was considered to be high, especially those belonged to Zhuang nationality were higher than the Hans. The carrier rate of ααWS/was higher, with CD41-42 the most common genotype.