ABCC11 gene encodes a transmembrane protein (MRP8) that transports various molecules across cell membranes. A SNP in this gene determines the human earwax (a secretory product of apocrine ceruminous gland) type which is a dimorphic Mendelian trait of wet and dry type. Previous studies revealed that this SNP exhibits remarkable geographical diversity across different human populations. The dry type of earwax is predominantly high among the East and South-East Asian populations and thereafter spread throughout the world whereas the wet type is high among European and African populations. Moreover, the degree of colostrum secretion is also associated with the type of earwax. Additionally, ABCC11 genotypes have been linked to diverse phenotypic traits including body odour, breast cancer susceptibility and response to certain drugs as therapeutic agents. The wild type of ABCC11 gene has higher relative risk of developing breast cancer compare to mutant allele though the actual pathophysiological mechanism behind developing breast cancer is still unknown. The earwax type can be used as genetic marker in population genetic studies shedding light on population variation, human migration and adaptation. This gene polymorphism has wide range of biomedical research applications that enables a comprehensive understanding of genetic diversity and facilitating personalised medicine approaches.
