Gnaq, short for guanine nucleotide binding protein G(q) subunit alpha, encodes the alpha subunit of the heterotrimeric G protein Gq. It functions in signal transduction through G-protein coupled receptors, activating downstream pathways such as phospholipase C, and is crucial for various physiological homeostasis processes [3,4].

Mutations in Gnaq are associated with multiple diseases. In over 90% of uveal melanoma patients, Gnaq/Gna11 mutations lead to signal transduction to downstream growth factors [1]. In zebrafish models, patient-derived Gnaq (GnaqQ209L) mutations combined with tp53M214K/M214K drive uveal melanoma, showing that YAP signaling is a major mediator of uveal melanoma and MITF acts as a tumor suppressor in this context [6]. Somatic, mosaic Gnaq mutations cause port-wine birthmarks, characterized by dilated, dysfunctional blood vessels, and when involving eyes and/or brain, result in Sturge-Weber syndrome [2]. Also, Gnaq mutations are present in capillary malformations, the most common vascular malformation [5].

In conclusion, Gnaq is essential for normal signal transduction via G-protein coupled receptors. Studies using genetic models like zebrafish have revealed its role in the development of uveal melanoma. Its mutations are strongly associated with various vascular and pigmentary diseases, highlighting the importance of understanding Gnaq's function for developing targeted therapies for these conditions.