A SNP in the ABCC11 gene is the determinant of human earwax type

  • Nat Genet. 2006 Mar;38(3):324-30. doi: 10.1038/ng1733.
Koh-ichiro Yoshiura  1 ,  Akira Kinoshita ,  Takafumi Ishida ,  Aya Ninokata ,  Toshihisa Ishikawa ,  Tadashi Kaname ,  Makoto Bannai ,  Katsushi Tokunaga ,  Shunro Sonoda ,  Ryoichi Komaki ,  Makoto Ihara ,  Vladimir A Saenko ,  Gabit K Alipov ,  Ichiro Sekine ,  Kazuki Komatsu ,  Haruo Takahashi ,  Mitsuko Nakashima ,  Nadiya Sosonkina ,  Christophe K Mapendano ,  Mohsen Ghadami ,  Masayo Nomura ,  De-Sheng Liang ,  Nobutomo Miwa ,  Dae-Kwang Kim ,  Ariuntuul Garidkhuu ,  Nagato Natsume ,  Tohru Ohta ,  Hiroaki Tomita ,  Akira Kaneko ,  Mihoko Kikuchi ,  Graciela Russomando ,  Kenji Hirayama ,  Minaka Ishibashi ,  Aya Takahashi ,  Naruya Saitou ,  Jeffery C Murray ,  Susumu Saito ,  Yusuke Nakamura ,  Norio Niikawa
Affiliations
  • 1. Department of Human Genetics, Nagasaki University Graduate School of Biomedical Sciences, Nagasaki, Japan. [email protected]
PMID: 16444273 DOI: 10.1038/ng1733
Abstract

Human earwax consists of wet and dry types. Dry earwax is frequent in East Asians, whereas wet earwax is common in other populations. Here we show that a SNP, 538G --> A (rs17822931), in the ABCC11 gene is responsible for determination of earwax type. The AA genotype corresponds to dry earwax, and GA and GG to wet type. A 27-bp deletion in ABCC11 exon 29 was also found in a few individuals of Asian ancestry. A functional assay demonstrated that cells with allele A show a lower excretory activity for cGMP than those with allele G. The allele A frequency shows a north-south and east-west downward geographical gradient; worldwide, it is highest in Chinese and Koreans, and a common dry-type haplotype is retained among various ethnic populations. These suggest that the allele A arose in northeast Asia and thereafter spread through the world. The 538G --> A SNP is the first example of DNA polymorphism determining a visible genetic trait.