By Xinhua
Washington : Scientists from Iceland and Sweden report in a paper published Thursday in the journal Science the discovery of two common single letter variations (SNPs) in the sequence of the human genome that appear to account for virtually all cases of a major subtype of glaucoma.
Scientists from deCODE genetics in Iceland and collaborators in Sweden said in their papers that the SNPs are located in the LOXL1 gene on chromosome 15, and confer respectively 26-fold and 8-fold increases in risk of exfoliation glaucoma (XFG) compared to the low-risk versions of the same markers.
The LOXL1 protein encoded by the gene is involved in the formation of elastin fibers which, when they accumulate in the eye, cause XFG.
“The risk conferred by these variants is such that it accounts for virtually all cases of exfoliation glaucoma, meaning that if we can neutralize the impact of these variants we might eliminate the disease,” said Kari Stefansson, CEO of deCODE.
“The LOXL1 protein made by this gene appears to play a role in the accumulation of microfibullar deposits that causes XFG, providing a promising mechanism to target for developing therapy. We plan to conduct additional studies to examine how we can take advantage of this finding to begin drug discovery,” added Stefansson.
Glaucoma is one of the most common causes of blindness worldwide. There are various types of glaucoma, all of which lead to damage in the optic nerve and progressive loss of vision. Exfoliation glaucoma is caused by the buildup of fibrous deposits on the surfaces on the front of the eye.
Between 10-20 percent of people over the age of 60 are believed to have some degree of exfoliation syndrome, and perhaps more than half of these individuals will go on to develop exfoliation glaucoma.