Blue and green eyes are exotic and beautiful, but researchers are finding that there’s a price attached to these colorful orbs. In a recent study, researchers found mutations in genes that control eye color apparently also influence eye cancer risks
– the lighter the eye color (and the fairer the skin color), the higher the cancer susceptibility.
The link between light skin and skin cancer has ample evidence from clinical and epidemiological studies. In addition, evidence also suggest that light-skinned individuals also have an increased risk for eye cancer, also known as uveal melanoma. However, the incidence of this condition is relatively low and no one has yet to establish the genetic link between light eyes and eye cancer.
Now, for the first time, scientists at the Ohio State University (OSU) and New York University (NYU) conducted a study to identify the genetic mechanisms underlying this link. Their results are unfortunate – the genetic changes in genes controlling eye color are also the ones responsible for increased risk of eye cancer.
The result came from studying 270 patients with uveal melanoma and screening their genetic profile for alterations that are linked to skin cancer. In the end, 5 mutations were associated with eye cancer risk. And of the 5, three were in genes that control eye color.
"Genetic susceptibility to uveal melanoma has been traditionally thought to be restricted only to a small groups of patients with family history. Now our strong data shows the presence of novel genetic risk factors associated with this disease in a general population of uveal melanoma patients," said Tomas Kirchhoff, Assistant Professor at the NYU School of Medicine, who is led the study.
"But this data is also important because it indicates -- for the first time -- that there is a shared genetic susceptibility to both skin and uveal melanoma mediated by genetic determination of eye color. This knowledge may have direct implications in the deeper molecular understanding of both diseases," adds Kirchhoff.
Eye cancer is relatively rare; however, it still affects around 2,500 patients every year.
"This is a very important discovery that will guide future research efforts to explore the interactions of these pigmentary genes with other genetic and environmental risk factors in cancers not linked to sun exposure, such as eye melanoma. This could provide a paradigm shift in the field. Our study suggests that in eye melanoma the pigmentation difference may play a direct cancer-driving role, not related to sunlight protection," said co-author Mohamed Abdel-Rahman.
Additional source: Ohio State University press release