Department of Medical Genetics, School of Basic Medical Sciences, Southern Medical University, Guangzhou, Guangdong, 510515, China.
Clin Genet. 2013 May;83(5):472-6. doi: 10.1111/cge.12021. Epub 2012 Oct 10.
The HKαα allele is a rearrangement occurring in the α-globin gene cluster containing both the -α(3.7) and ααα(anti4.2) unequal crossover junctions. The anti-HKαα allele is the reciprocal product containing both the -α(4.2) and ααα(anti3.7) unequal crossover junctions, which had been predicted but had not been detected previously. The phenotypic feature and population frequency of these two unusual alleles were not described. We report the identification of nine individuals carrying the HKαα allele and two individuals carrying the anti-HKαα allele in southern China and describe their phenotype and haplotype data. The molecular structures of HKαα allele and anti-HKαα allele were confirmed by two-round nested polymerase chain reaction assay. The mechanism of origin of both alleles is related to probably simultaneous double crossover. Heterozygotes of HKαα or anti-HKαα allele show a normal hematological phenotype. Finally, we report the carrier rates of these both alleles in the Guangxi Zhuang Autonomous Region of southern China, namely, ∼0.07% for the HKαα allele and ∼0.02% for the anti-HKαα allele.
HKαα 等位基因是一种发生在α-球蛋白基因簇中的重排，其中包含-α(3.7)和 ααα(anti4.2)不等交换连接。反-HKαα 等位基因是包含-α(4.2)和 ααα(anti3.7)不等交换连接的逆产物，以前曾预测过，但尚未检测到。这两个不寻常等位基因的表型特征和群体频率尚未描述。我们报告了在中国南方发现的九个携带 HKαα 等位基因和两个携带反-HKαα 等位基因的个体，并描述了它们的表型和单倍型数据。通过两轮巢式聚合酶链反应试验证实了 HKαα 等位基因和反-HKαα 等位基因的分子结构。这两个等位基因的起源机制可能与同时发生的双重交叉有关。HKαα 或反-HKαα 等位基因的杂合子表现出正常的血液学表型。最后，我们报告了这两个等位基因在中国南方广西壮族自治区的携带率，即 HKαα 等位基因约为 0.07%，反-HKαα 等位基因约为 0.02%。
