[Skip to Content]
[Skip to Content Landing]
Invited Commentary
January 2019

Penetrance of Myocilin Mutations—Who Gets Glaucoma?

Author Affiliations
  • 1Department of Ophthalmology and Visual Sciences, Carver College of Medicine, University of Iowa, Iowa City
JAMA Ophthalmol. 2019;137(1):35-37. doi:10.1001/jamaophthalmol.2018.4470

Mutations in the myocilin (MYOC) gene were discovered as a cause of primary open-angle glaucoma (POAG) in 1997.1 Twenty-one years later, mutations in MYOC remain the most common molecularly defined cause of glaucoma and are responsible for 3% to 4% of adult-onset POAG cases.2 Glaucoma associated with MYOC is transmitted with autosomal dominant inheritance3; offspring from parents with glaucoma caused by a MYOC mutation have a 50% chance of inheriting the mutation and increased risk for glaucoma. The most common glaucoma-associated MYOC mutation is a nonsense mutation, Gln368Stop, that produces truncated MYOC protein that is missing its last quarter.2 This mutation has been detected in 1.6% of patients with POAG in large case-control studies and is responsible for more glaucoma than any other known mutation.2 In their article in JAMA Ophthalmology, Han et al4 evaluated very large study populations to investigate just how high the risk for glaucoma is for those with this MYOC mutation.