Reverse Phenotyping in Patients with Skin Capillary Malformations and Mosaic GNAQ or GNA11 Mutations Defines a Clinical Spectrum with Genotype-Phenotype Correlation.

Postzygotic mutations in the genes GNAQ/GNA11 encoding heterotrimeric G protein alpha subunits account for skin mosaic conditions with vascular or pigmentary anomalies (Couto et al., 2017; Shirley et al., 2013; Siegel et al., 2018; Thomas et al., 2016). We sought to delineate the phenotype of 32 patients with skin capillary malformations (CMs) harboring an activating postzygotic mutation in GNA11 or GNAQ in affected skin. Nevus flammeus, ipsilateral segmental overgrowth, varicose veins, and macrocephaly were associated with GNAQ mutations, whereas cutis marmorata, nevus anemicus, and ipsilateral hypotrophy were associated with GNA11 mutations.