The Sturge–Weber syndrome and port-wine stains are caused by a somatic activating mutation in GNAQ. Whole-genome sequencing of DNA from paired samples of visibly affected and normal tissue from 3 persons with the Sturge–Weber syndrome was performed. A non-synonymous single-nucleotide variant (c.548G?A, p.Arg183Gln) was identified in GNAQ in samples of affected tissue from 88% of the participants (23 of 26) with the Sturge–Weber syndrome and from 92% of the participants (12 of 13) with apparently nonsyndromic port-wine stains. This variant was not identified in any of the samples of affected tissue from 4 participants with an unrelated cerebrovascular malformation or in any of the samples from the 6 controls.
added by Yannis Trakadis, MD