Variations in LOXL1 gene linked to exfoliation glaucoma

REYKJAVIK, Iceland — Two common single letter variations in the human genome sequence appear to account for virtually all cases of exfoliation glaucoma, according to a press release from deCODE genetics.

Researchers at the National University Hospital in Reykjavik, at Uppsala University in Sweden and at deCODE genetics discovered the two single letter variations (SNPs), which are located on the LOXL1 gene on chromosome 15. They made the discovery by analyzing more than 300,000 SNPs in Icelandic and Swedish glaucoma patients and control subjects using the Hap300 SNP chip (Illumina), according to the release.

Approximately 25% of the study patients had two copies of the highest-risk variant, which increases their likelihood of developing exfoliation glaucoma by about 100 times compared with patients with the low-risk version of the same SNP, the release said.

The LOXL1 protein encoded by the gene is involved in the formation of elastin fibers that cause exfoliation glaucoma when they accumulate in the eye.

"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, in the release. "The LOXL1 protein made by this gene appears to play a role in the accumulation of microfibullar deposits that causes [exfoliation glaucoma], providing a promising mechanism to target for developing therapy."

The study is published online ahead of print on the Web site for Science.