Fig. (1).

(A) The genomic structures of ABCC11 and ABCC12 genes on human chromosome 16q12.1. The cytogenetic location of the ABCC11 gene as well as the structures of exons and introns were analysed by BLAST searches on the human genome. The ABCC11 gene is encoded by a -68 kb gene consisting of 30 exons. A non-synonymous SNP: 538G>A (Gly180Arg), an earwax determinant, is in the exon 4 of ABCC11 gene. (B) Schematic illustration of ABCC11 structure and hitherto known non-synonymous SNPs. ABCC11 has a total of 12 transmembrane (TM) regions and two intracellular ATP-binding cassettes. Asn838 and Asn844 residing in an extracellular loop between transmembrane helices TM7 and TM8 are N-linked glycosylation sites in the ABCC11 WT protein. Locations of hitherto reported nonsynonymous SNPs and Δ27 (rare deletion mutation) are indicated in the putative structure of ABCC11. G180R and Δ27 are related with the formation of dry-type earwax.