Mapping of the wet/dry earwax locus to the pericentromeric region of chromosome 16.

Human earwax is a one-gene trait comprising two phenotypically distinct forms--wet and dry. This trait is attributed to secretory products of the ceruminous apocrine glands, and frequencies of phenotypes vary between ethnic groups. We did linkage analysis of eight Japanese families segregating earwax dimorphism. We assigned the earwax locus within a approximately 7.42-cM region between the loci D16S3093 and D16S3080 on chromosome 16p11.2-16q12.1, with a maximum two-point LOD score of 11.15 (theta;=0.00) at the locus D16S3044. Identification of the earwax locus could contribute to further anthropogenetic studies and physiological and pathological understanding of the apocrine-gland development.