An international, multi-centre study has found a novel oncogene that is associated with uveal melanoma, the most common form of eye cancer.

Researchers have isolated an oncogene called GNA11 and have discovered that it is present in more than 40% of tumour samples taken from patients with uveal melanoma.

"These findings are significant because we now have a much better understanding of the precise mechanism of this disease, which may yield targets and treatments in the future, said Boris C Bastian, senior author of the study.

"Currently, once this type of melanoma has spread beyond the eye, therapeutic options are extremely limited," added Dr Bastian.

Most frequently, melanomas of the eye occur in the part of the eye known as the uveal tract-the vascular layer that includes the iris (the pigmented cells surrounding the pupil), the ciliary body (the ring-shaped muscle that changes the size of the pupil and the shape of the lens when the eye focuses), and the choroid (the pigmented layer under the retina).

Most patients with melanoma of the eye experience no symptoms until the tumor has become large enough to cause vision problems.

In this study, DNA was extracted from tumor samples of patients and genetic sequencing was performed. To validate this new oncogene, immunocompromised mice were injected with cells engineered to harbor the mutated genes and monitored for the formation of tumors.

Based on this latest research and recent studies, 83 percent of uveal melanomas are now known to have an active mutation in the GNAQ or GNA11 oncogenes.