OPTN and neurodegenerative disease: Heterozygous mutations in OPTN have previously been linked to glaucoma and amyotrophic lateral sclerosis, although sequencing all exons of the OPTN gene in all seven patients identified as outliers revealed no such mutations, and no patients had any clinical features of glaucoma or neurodegenerative disease (data not shown).38 We were able to identify a haplotype that demonstrated a strong correlation with OPTN expression.