Two genetic variants associated with basal cell carcinoma (BCC) are identified online this week in Nature Genetics. BCC is the most common cancer among individuals of European ancestry and can be disfiguring, although it is less lethal than other forms of skin cancer.
Unnur Thorsteinsdottir, Kari Stefansson and colleagues carried out a genome-wide association study of Icelanders with and without BCC, and followed up with replication studies of additional populations of affected individuals in Iceland and Eastern Europe. They identify two variants in different regions of chromosome 1 as predisposing to BCC. Previously identified BCC-associated risk variants were also associated with fair skin, but the chromosome 1 variants were not, suggesting that they increase risk of the disease through a distinct pathway.
Taking into account all such genetic risk factors found to date, the authors show that those individuals with two copies of all known risk variants have an increased risk of more than 12 times compared to those individuals who have two copies of each of the non-risk versions.