GNAQ Mutations in Diffuse and Solitary Choroidal Hemangiomas

Purpose: GNAQ mutations have been identified in port wine stains (both syndromic and nonsyndromic) and melanocytic ocular neoplasms. This study investigates the presence of GNAQ mutations in diffuse (those associated with Sturge–Weber syndrome [SWS]) and solitary choroidal hemangiomas. Participants: Tissue from 11 patients with the following diagnoses: port wine stain (n = 3), diffuse choroidal hemangioma (n = 1), solitary choroidal hemangioma (n = 6), and choroidal nevus (n = 1). Methods: Ten specimens were interrogated with Memorial Sloan Kettering-Integrated Mutation Profiling of Actionable Cancer Targets, a hybridization capture-based next-generation sequencing assay for targeted deep sequencing of all exons and selected introns of 468 key cancer genes in formalin-fixed, paraffin-embedded tumors. Digital polymerase chain reaction was used to detect GNAQ Q209 mutation in 1 specimen. Main Outcome Measures: Detection of GNAQ codon-specific mutation. Results: Activating somatic GNAQ mutations (c.547C > T; p.Arg183Cys) were found in 100% (3 of 3) of the port wine stain and in the diffuse choroidal hemangioma. Somatic GNAQ mutations (c.626A > T; p.Gln209Leu) were found in 100% (6 of 6) of the solitary choroidal hemangiomas and (c.626A > C; p.Gln209Pro) in the choroidal nevus. Conclusions: GNAQ mutations occur in both diffuse and solitary hemangiomas, although at distinct codons. An R183 codon is mutant in diffuse choroidal hemangiomas, consistent with other Sturge–Weber vascular malformations. By contrast, solitary choroidal hemangiomas have mutations in the Q209 codon, similar to other intraocular melanocytic neoplasms.