PT  - JOURNAL ARTICLE
AU  - Hildebrand, Michael S.
AU  - Harvey, A. Simon
AU  - Malone, Stephen
AU  - Damiano, John A.
AU  - Do, Hongdo
AU  - Ye, Zimeng
AU  - McQuillan, Lara
AU  - Maixner, Wirginia
AU  - Kalnins, Renate
AU  - Nolan, Bernadette
AU  - Wood, Martin
AU  - Ozturk, Ezgi
AU  - Jones, Nigel C.
AU  - Gillies, Greta
AU  - Pope, Kate
AU  - Lockhart, Paul J.
AU  - Dobrovic, Alexander
AU  - Leventer, Richard J.
AU  - Scheffer, Ingrid E.
AU  - Berkovic, Samuel F.
TI  - Somatic <em>GNAQ</em> mutation in the <em>forme fruste</em> of Sturge-Weber syndrome
AID  - 10.1212/NXG.0000000000000236
DP  - 2018 Jun 01
TA  - Neurology Genetics
PG  - e236
VI  - 4
IP  - 3
4099  - http://ng.neurology.org/content/4/3/e236.short
4100  - http://ng.neurology.org/content/4/3/e236.full
SO  - Neurol Genet2018 Jun 01; 4
AB  - Objective To determine whether the GNAQ R183Q mutation is present in the forme fruste cases of Sturge-Weber syndrome (SWS) to establish a definitive molecular diagnosis.Methods We used sensitive droplet digital PCR (ddPCR) to detect and quantify the GNAQ mutation in tissues from epilepsy surgery in 4 patients with leptomeningeal angiomatosis; none had ocular or cutaneous manifestations.Results Low levels of the GNAQ mutation were detected in the brain tissue of all 4 cases—ranging from 0.42% to 7.1% frequency—but not in blood-derived DNA. Molecular evaluation confirmed the diagnosis in 1 case in which the radiologic and pathologic data were equivocal.Conclusions We detected the mutation at low levels, consistent with mosaicism in the brain or skin (1.0%–18.1%) of classic cases. Our data confirm that the forme fruste is part of the spectrum of SWS, with the same molecular mechanism as the classic disease and that ddPCR is helpful where conventional diagnosis is uncertain.ddPCR=droplet digital PCR; LMA=leptomeningeal angiomatosis; SWS=Sturge-Weber syndrome