AIM: Approximately 40-60% of melanomas from Caucasian populations carry 
activating mutations in the BRAF oncogene, with the most common being the 
p.Val600Glu (V600E) hotspot mutation in exon 15. The aim of the present study 
was to investigate the frequency of the less common p.Val600Lys (V600K) mutation 
in metastatic melanoma from a high incidence region.
METHOD: Dideoxy sequencing and fluorescent single strand conformation analysis 
were used to screen for mutations in exon 15 of BRAF in 183 cases of metastatic 
melanoma.
RESULTS: The overall incidence of BRAF mutation (89/183, 49%) was very similar 
to other large studies of Caucasian populations. However, the frequency of the 
p.Val600Lys mutation was higher than in most other studies and comprised almost 
one-third of all BRAF mutations in our cohort (27/89, 30%).
CONCLUSION: BRAF p.Val600Lys mutations were present at a relatively high 
frequency in this cohort of metastatic melanoma patients (27/183, 15%). Assays 
used to screen for BRAF mutations in the clinic should be robust enough to 
detect the p.Val600Lys mutation, as this may have therapeutic implications.