Ear wax comes in two forms, wet and dry, and is determined by a single gene that is implicated in controlling the development of the apocrine glands. In 8 June The Lancet, Hiroaki Tomita and colleagues from Nagasaki University School of Medicine, Japan, describe the chance discovery of the location for the gene that codes for ear wax on chromosome 16 (Lancet 2002, 359:2000-2002).

Tomita et al. performed a linkage analysis of eight Japanese families with wet ear wax (Japanese populations usually have dry wax) and paroxysmal kinesigenic choreoathetosis — a neurological disorder characterized by intermittent uncontrollable twisting movements of the extremities. They localized the earwax locus to a ~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 (θ=0·00) at the locus D16S3044. The ear wax locus was located on the same area of chromosome 16 as the gene responsible for paroxysmal kinesigenic choreoathetosis.

"Identification of the earwax locus could contribute to further anthropogenetic studies and to physiological and pathological understanding of apocrine-gland development," speculated Tomita.