124例HbH患者α珠蛋白基因的分析

An analysis of α globin genes in 124 cases with HbH diseaseS

目的分析１２４例ＨｂＨ患者的α珠蛋白基因的分子缺陷状况及其分布，为ＨｂＨ的基因诊断和产前诊断提供科学依据。方法应用Ｓｏｕｔｈｅｒｎ印迹杂交、限制性内切酶分析ＰＣＲ产物、血红蛋白电泳和ＬｏｎｇＰＣＲ等技术，对受检ＨｂＨ病患者的α珠蛋白基因组织进行了鉴定。结果在１２４例ＨｂＨ病患者中，缺失型患者有８３例，占６６．９％；其中右侧缺失型（α－３．７）４５例，占缺失型患者总数的５４．２％，主要分布于广东、湖北、云南等省区，左侧缺失型（α－４．２）３８例，占缺失型患者总数的４５．８％，主要分布在广西和江西；非缺失型患者４１例，占３３．１％；其中ＨｂＣｏｎｓｔｎｔＳｐｒｉｎｇ（ＨｂＣＳ）患者９例，占非缺失型患者总数的２２．０％，Ｈｂ广西（ＨｂＱＳ）患者３例，占非缺失型患者总数的７．３％，其他α＋地贫突变类型２９例，占非缺失型总数的７０．７％。结论不同地区ＨｂＨ患者的α珠蛋白基因的突变类型有明显的差异，该项研究为ＨｂＨ病的分子遗传学和ＨｂＨ病的基因诊断提供了依据。

Objective To analyze the molecular abnormalities as well as the distribution of α globin genes in 124 cases with HbH disease; and provide scientific basis for molecular diagnosis and prenatal diagnosis in this hemoglobin disorder. Methods α globin gene tissue of 124 cases with HbH disease were analyzed by Southern blot hybridization, restriction mapping of PCR products, hemoglobin electrophoresis and Long PCR technology. Results In 124 cases, 83 were identified to be the deletional type, accounting for 66.9%. Among the 83,45 cases belonged to the rightward type of deletion (α -3.7 ) and 38 cases were leftward type of deletion (α -4.2 ). The patients with rightward type of deletion mainly distributed in Guangdong, Hubei and Yunnan provinces, while patients with leftward type of deletion lived in Guangxi and Jiangxi. Another 41 cases were identified as non deletional type of HbH disease, acounting for 33.1% of the tested cases. Among these patients, 9 cases were HbConstant Spring (HbCS) and 3 were HbQong Sze(HbQS). The other remaining 29 cases were α + thalassemia mutations which occupied 70.7% of the total non deletional cases. Conclusion The molecular abnormalities of α globin genes in HbH patients were significantly different in different regions. This study provides useful knowledge for the understanding the molecular genetics of HbH disease as well as for molecular diagnosis in the regions where the disease is prevalent.