Pigmentary glaucoma may be a highly heritable condition that could also have genetic links to myopia and lighter eye color, a study in JAMA Ophthalmology suggests.

Since the cause of pigmentary glaucoma is still not well understood, a team of researchers analyzed its single-nucleotide polymorphism (SNP) heritability and other possible genetic associations.

The genome-based investigation included patients from Europe: 227 with pigmentary glaucoma from Germany and 291 healthy patients in the control group from the United Kingdom.

With data from a 10-year period, the researchers found a relatively high SNP heritability rate of 45% for pigmentary glaucoma.

Additionally, this condition appeared genetically distinct from primary open-angle glaucoma and its endophenotypes. But the study found some SNPs associated with eye color and myopia appeared to be correlated with pigmentary glaucoma.

Specifically, 12 SNPs previously found to have genome-wide significant associations with eye pigment were linked to pigmentary glaucoma (4.9%). The researchers also observed a moderate correlation between pigmentary glaucoma SNP effect sizes and myopia and a greater association with iris pigmentation, although neither were significant after adjusting with a strict significance threshold, the study noted.

Simcoe MJ, Weisschuh N, Wissinger B, et al. Genetic heritability of pigmentary glaucoma and associations with other eye phenotypes. JAMA Ophthalmol. January 30, 2020. [Epub ahead of print].