Hori Yusuke S, Yamada Aiko, Matsuda Norifumi, Ono Yusuke, Starenki Dmytro, Sosonkina Nadiya, Yoshiura Koh-Ichiro, Niikawa Norio, Ohta Tohru
1 Research Institute of Personalized Health Sciences, Health Sciences University of Hokkaido, Tobetsu, Japan.
2 Department of Neurological Surgery, National Hospital Organization Okayama Medical Center, Okayama, Japan.
Hum Biol. 2017 Oct;89(4):305-307.
A single nucleotide polymorphism in the ABCC11 gene, 538G>A (rs17822931), is known to determine human ear wax type. The G/G and G/A genotypes correspond to the wet type, while the A/A genotype corresponds to the dry type. Another earwax determinant, a 27-bp deletion (Δ27) downstream from the rs17822931 site, is a rare variant that leads to the dry phenotype. In a previous report, we found an individual with the G allele who unexpectedly showed the dry type of earwax, leading to the identification of Δ27. We also demonstrated that the Δ27 allele was present in individuals of Japanese, Thai, native North American, Andean, and Bolivian ancestry but absent in those of European and African ancestry. Here, we assessed the Δ27 allele frequency among Japanese and Ukrainian individuals and identified a novel association between the Δ27 and 538G>A mutations. The Δ27 allele frequency was 0.002 (3/1,520; one individual is heterozygous, and another is homozygous) among Japanese individuals and 0 (0/794) among Ukrainians. We also found a previously unreported homozygous genotype for both the Δ27 and A alleles. Our findings suggest that the Δ27 deletion may have occurred in an ABCC11 gene with the 538G>A mutation.
已知ABCC11基因中的单核苷酸多态性538G>A（rs17822931）可决定人类耳垢类型。G/G和G/A基因型对应湿性耳垢，而A/A基因型对应干性耳垢。另一个耳垢决定因素是rs17822931位点下游27个碱基对的缺失（Δ27），这是一种导致干性表型的罕见变异。在之前的一份报告中，我们发现了一名携带G等位基因但意外表现出干性耳垢的个体，从而鉴定出了Δ27。我们还证明，Δ27等位基因存在于日本、泰国、北美原住民、安第斯和玻利维亚血统的个体中，但在欧洲和非洲血统的个体中不存在。在这里，我们评估了日本和乌克兰个体中Δ27等位基因的频率，并确定了Δ27与538G>A突变之间的新关联。在日本个体中，Δ27等位基因频率为0.002（3/1520；一名个体为杂合子，另一名个体为纯合子），在乌克兰个体中为0（0/794）。我们还发现了一种之前未报道的Δ27和A等位基因的纯合基因型。我们的研究结果表明，Δ27缺失可能发生在具有538G>A突变的ABCC11基因中。
