These G-alpha protein mutations occur in the genes GNAQ and GNA11 and are seen at a high frequency in uveal melanomas, those melanomas that begin in the eye.
Deep sequencing studies show that 4.2% of tumours carry activating mutations in GNAS (encoding Gαs), and that oncogenic activating mutations in genes encoding Gαq family members (GNAQ or GNA11) are present in ~66% and ~6% of melanomas arising in the eye and skin, respectively.
The mutations, such as those in NRAS, BRAF, GNAQ and GNA11, promote the growth of melanoma cells in most part through the mitogen-activated protein kinase (MAPK) pathway.
Sequencing of melanoma driver genes revealed GNAQ (p.Q209L) mutations in two samples; although it is possible that these samples represent extraocular spread of an occult uveal melanoma.