The Role of BRAF^V600E Mutation in the Development of Nevi

Although it is known that up to 80% of nevi harbor BRAF^V600E mutations, it has not been clear whether mutations occur in the development of the nevus or whether the BRAF change develops later, after other nevus-initiating events have already been triggered. One way to address this controversy is to analyze the cell-by-cell genetic profile within nevus lesions. If mutation occurred early on, then most, if not all, of the cells should harbor the BRAF mutation. If mutation was a late event, then only some cells should contain the mutation.

These authors used droplet digital polymerase chain reaction to assess the frequency of cells with BRAF^V600E mutations within acquired nevi. In BRAF-mutant nevi, the number of BRAF-mutant alleles equaled the …