云南少数民族地区新生儿α-珠蛋白生成障碍性贫血基因型研究

Research of the genotype α-thalassemia in newborn of Yunnan minority nationality

目的了解云南少数民族地区新生儿α-珠蛋白生成障碍性贫血基因携带率及基因型,为云南α-珠蛋白生成障碍性贫血三级预防提供依据。方法以毛细管电泳检测新生儿干血斑及抗凝血标本血红蛋白(Hb)Bart's水平,以跨越裂隙PCR(gap-PCR)、荧光定量PCR熔解曲线法检测常见缺失(--SEA/αα、-α3.7/αα、-α4.2/αα)及突变(αCSα/、αQSα/和αWSα/),对HbBart's≥0.1%的样本再行多重PCR检测罕见缺失(--THAI/αα,--FIL/αα,--MED/αα,-α20.5/αα)及DNA测序分析。结果文山州210例新生儿标本中,检出α-珠蛋白生成障碍性贫血基因19例(9.0%),其中α2-珠蛋白基因罕见突变αα/αTα6例(31.6%),--FIL/αα缺失5例(26.3%),-α3.7/αα缺失4例(21.05%),--SEA/αα缺失4例(21.05%);德宏州198例新生儿标本中α-珠蛋白生成障碍性贫血基因16例(8.1%),其中--FIL/αα缺失7例(43.7%)、-α3.7/αα缺失5例(31.3%),αCSα/突变2例(12.5%)、α2-珠蛋白基因罕见突变αα/αTα2例(12.5%);文山州及德宏州两少数民族地区新生儿α-珠蛋白生成障碍性贫血基因携带率分别为9.0%、8.1%,基因型5种(--FIL/αα、-α3.7/αα、--SEA/αα缺失、αCSα/及罕见突变αα/αTα),以--FIL/αα缺失及αα/αTα罕见突变为主。结论云南文山及德宏两少数民族地区新生儿α-珠蛋白生成障碍性贫血基因型构比与国内相关报道明显不同;云南少数民族地区α-珠蛋白生成障碍性贫血基因筛查应涵盖罕见--FIL/αα缺失和罕见突变检测。

Objective To explore the genecarrying rate and the genotype ofα-thalassemia in the newborns of different ethnic groups in Yunnan minority nationality,and to provide scientific basis for the"three-step-prevention"ofα-thalassemia in Yunnan province.Methods The HbBart′s contents of newborn′s dried blood stains and anticoagulant specimens were analyzed by capilary electrophoresis,three types of deletion(--^SEA/αα,-α^3.7/αα,-α^4.2/αα)and three types of mutation(α^CSα,α^QSαandα^WSα)were detected by using Gap-PCR and the melting curve of the fluoresce quantitative PCR,multiplex-PCR were used to samples with HbBart′s content above 0.1%for four types of rare deletion(--^THAI/αα,--^FIL/αα,--^MED/αα,-α^20.5/αα),while DNA sequencing was also applied.Results Nineteen cases ofα-thalassemia(9.0%)were detected from 210 newborns in Wenshan state,including 6 cases of rare mutation ofαα/αTαwithα2-bulbin-protein gene(31.6%),5 cases of deletion--^FIL/αα(26.3%),4 cases of deletion-α^3.7/αα(21.05%),and 4 cases of deletion--^SEA/ααdeletion(21.05%);16 cases ofα-thalassemia(8.1%)were detected from 198 newborns in Dehong state,including 7 cases of deletion--^FIL/αα(43.7%),5 cases of-α^3.7/αα(31.30%),2 cases of mutationα^CSα(21.05%),2 cases of rare mutationɑɑ/ɑ^Tɑwithα2-bulbin-protein gene(12.5%).The gene frequency ofɑ-thalassemia in the newborns from the ethnic groups in Wenshan and Dehong Prefecture were 9.0%and 8.1%respectively with five genotypes(--^FIL/αα,-α^3.7/αα,--^SEA/ααdeletion,αCSαand rare mutationαα/α^Tα).Conclusion The genotypes ofα-thalassemia in the newborns from the ethnic groups in Wenshan and Dehong were distinctively different from other reported in China;The screening ofα-thalassemia in ethnic groups in Yunnan should cover the rare deletion of--^FIL/ααand rare mutations mentioned above in the future.