GNAQ/GNA11 Mosaicism Causes Aberrant Calcium Signaling Susceptible to Targeted Therapeutics

Mosaic variants in genes GNAQ or GNA11 lead to a spectrum of vascular and pigmentary diseases including Sturge-Weber syndrome, in which progressive postnatal neurological deterioration led us to seek biologically targeted therapeutics. Using two cellular models, we find that disease -causing GNAQ / 11 variants hyperactivate constitutive and G -protein coupled receptor ligand-induced intracellular calcium signaling in endothelial cells. We go on to show that the aberrant ligand-activated intracellular calcium signal is fueled by extracellular calcium influx through calcium -release -activated channels. Treatment with targeted small interfering RNAs designed to silence the variant allele preferentially corrects both the constitutive and ligand-activated calcium signaling, whereas treatment with a calcium -release -activated channel inhibitor rescues the ligand-activated signal. This work identifies hyperactivated calcium signaling as the primary biological abnormality in GNAQ/ 11 mosaicism and paves the way for clinical trials with genetic or small molecule therapies.