Exfoliation sydrome (XFS) is an age-related systemic disorder involving the extracellular matrix (ECM), characterized by the excessive production and progressive accumulation of an abnormal extracellular material in various tissues is the most common known cause of secondary glaucoma and a major cause of blindness worldwide. This disease is common in many populations, with an estimated 60–70 million individuals affected. Exfoliation glaucoma (XFG) has a worse prognosis than other major types of glaucoma, and it is often resistant to intraocular-pressure-lowering medical treatment, more often requiring laser and surgical intervention.
Variants in the LOXL1 gene were the first to be genetically associated with exfoliation syndrome. Subsequently, XFS-associated variants have been found in or near the CACNA1, POMP, TMEM136, AGPAT1, RBMS3, and SEMA6A loci. Variants found to date have had relatively minor effects and have also been subject to "allele reversal" between different populations. A strongly protective variant (rs201011613 in the LOXL1 gene) has also been found.[PMID 28553957]