LOXL1 and open-angle glaucoma: Recent genetic studies in multiple populations have identified the LOXL1 gene as a major contributor to the risk of developing PEX.20 Performing a genome-wide association study, Thorleifsson and co-workers19 first detected three common sequence variants or single nucleotide polymorphisms (SNPs) in the LOXL1 gene on chromosome 15q24.1 that were strongly associated with both PEX syndrome and PEX glaucoma, but not with POAG, in Scandinavians from Iceland and Sweden.