Forty-six cases of sporadic melanoma have been investigated for loss of heterozygosity at 4 loci: D11S29 (11q23), YNZ22 (17p13.3), TP53 (17p13.1); and NM23 (17q22). Each of the loci is thought to be important in the pathogenesis of other tumours. Mutations were found infrequently at the YNZ22, NM23, and TP53 loci. At D11S29, however, the frequency of mutation in the melanoma samples was high (67%) and mutations at this locus were associated with younger age at presentation. This region of chromosome 11 is also commonly mutated in breast cancers and haematological malignancies. Genetic aberrations at D11S29 may therefore represent nonspecific mutations found in several malignancies or part of a pathway common to the malignant phenotype.