Fucharoen S, Fucharoen G, Sae-ung N, Sanchaisuriya K, Fukumaki Y
Department of Clinical Chemistry, Faculty of Associated Medical Sciences, Khon Kaen University, Thailand.
Southeast Asian J Trop Med Public Health. 1997;28 Suppl 3:110-4.
Two hemoglobin variants that migrate abnormally on gel electrophoresis were found in four unrelated Thai individuals. One variant that migrate faster than HbA but more slowly than Hb Bart's was detected in two heterozygotes. Another abnormal Hb migrating between HbA2 and HbF was found in one heterozygote and one compound heterozygote with HbE. In all cases, no microcytic anemia was observed. PCR amplification and direct DNA sequencing established that the first variant was caused by a missense mutation at codon 83 (GGC-GAC) that leads to Gly to Asp substitution previously described as the Hb Pyrgos in a Greek boy. The second variant was caused by an AC insertion at the termination codon that leads to synthesis of elongated beta-globin chain known as the Hb Tak. Beta globin gene haplotype analysis demonstrated that each variant was found on the same chromosome background in Thai individuals. The simple non-radioactive DNA assays based on allele specific polymerase chain reaction for the detection of these two Hb mutations in a routine laboratory are described.
在4名无亲缘关系的泰国人中发现了两种在凝胶电泳中迁移异常的血红蛋白变体。在两名杂合子中检测到一种迁移速度比HbA快但比Hb Bart's慢的变体。在一名杂合子和一名与HbE的复合杂合子中发现了另一种在HbA2和HbF之间迁移的异常血红蛋白。在所有病例中，均未观察到小细胞贫血。聚合酶链反应（PCR）扩增和直接DNA测序确定，第一种变体是由密码子83处的错义突变（GGC-GAC）引起的，该突变导致甘氨酸被天冬氨酸取代，此前在一名希腊男孩中被描述为Hb Pyrgos。第二种变体是由终止密码子处的AC插入引起的，导致合成了一种延长的β-珠蛋白链，称为Hb Tak。β-珠蛋白基因单倍型分析表明，在泰国个体中，每种变体都出现在相同的染色体背景上。本文描述了基于等位基因特异性聚合酶链反应的简单非放射性DNA检测方法，用于在常规实验室中检测这两种血红蛋白突变。
