In the news

To identify genetic loci associated with melanoma.

The researchers from the melanoma genetics consortium undertook a genome-wide association study. The discovery phase involved nearly 3,000 melanoma patients of European and Israeli descent and over 7,500 controls of European descent. Single nucleotide polymorphisms (SNPs) showing evidence of association were further tested in a replication phase of 1,500 melanoma patients and 2,000 controls of European descent with data from both phases combined in a meta-analysis.

In addition to confirming several previously identified loci, the discovery phase highlighted seven further loci showing association. SNPs within these seven regions were genotyped in the replication phase with the combined analysis showing strong evidence of association for three loci located on chromosomes 2, 11, and 21 with a potential fourth locus also on chromosome 11.

The study reports three new loci associated with melanoma bringing the total known loci to 11. Half of these loci are thought to act through the skin pigmentation phenotype and a further three through nevus phenotype, suggesting that “at least two of the newly identified loci appear to influence risk through a new mechanism, opening up potential directions for melanoma research”.

This study not only confirmed several known loci but also identified three new associations that show no real link to well-known melanoma risk factors such as skin pigmentation and nevus count. Two of the three associations near the CASP8 and ATM genes have been previously linked to other cancers but the third locus on chromosome 21 near the MX2 gene has not. The study authors note that with larger study numbers it may be possible to identify additional novel loci further suggesting that alternative unknown mechanisms may play a role in disease aetiology, with further research required.