MITF p.E318K Prevalence Similar Regardless of CDKN2A
Mutation correlates with increased risk, especially for multiple primary melanoma, high nevi count
FRIDAY, Dec. 11, 2015 (HealthDay News) -- The prevalence of MITF p.E318K is similar in patients with melanoma, irrespective of the presence of CDKN2A mutations, according to a study published online Dec. 10 in JAMA Dermatology.
Miriam Potrony, from the Universitat de Barcelona in Spain, and colleagues examined the prevalence of MITF p.E318K in Spanish patients with melanoma. Genotyping was performed for 531 patients with melanoma: 271 with multiple primary melanoma (MPM) without mutations affecting p16INK4A; 191 probands from melanoma-prone families without mutations affecting p16INK4A; and 69 probands from families carrying CDKN2A mutations affecting p16INK4A. Controls were 499 age- and sex-matched cancer-free individuals from the Spanish National Bank of DNA.
The researchers found that the prevalence of MITF p.E318K was 1.9 percent in all melanoma patients with wild-type p16INK4A; 2.6 percent in patients with MPM; and 2.9 percent in probands of families with p16INK4A mutations. The MITF p.E318K variant correlated with increased melanoma risk (odds ratio, 3.3), especially in MPM and high nevi count (odds ratios, 4.5 and 8.4, respectively). Among two MITF p.E318K carriers, two fast-growing melanomas were detected during dermatologic digital follow-up.
"Testing for MITF p.E318K should not exclude patients with known mutations in p16INK4A," the authors write.