Abstract :
Background: Glaucoma is defined as progressive optic neuropathy leading to irreversible blindness if not treated on time. Primary open angle glaucoma (POAG) is most common form of glaucoma. Mutations in myocilin gene (MYOC) account for 2–4% of POAG cases.
Purpose: To identify and evaluate MYOC variants alleles among patients with POAG and their healthy first degree relatives.
Materials and Methods: 66 POAG patients and 26 healthy first degree relatives recruited for study. All patients underwent complete ophthalmic examination followed by genomic DNA (deoxyribonucleic acid) isolation from peripheral blood and quantification of DNA on spectrophotometer. All samples were amplified with each primer by PCR (Polymerase Chain Reaction) technique and amplified DNA and primer sequence checked again by electrophoresis for confirmation of specified MYOC gene mutation.
Results: We identified a known MYOC missense mutation, Pro370leu in 16 POAG cases and found consistent genotypic but not phenotypic correlation in 4 of their first degree relatives. Out of 16 cases, pathogenic MYOC gene variant was found in 12 adult onset POAG, 3 juvenile onset POAG, and 1 case of OHT.
Conclusion: This study is first of its kind in North India. Our study showed frequency of MYOC gene mutation in POAG cases was 24.24% which is much higher than found elsewhere in India and other countries (2-5%). Frequency of transmission of pathogenic MYOC gene variant in first degree relatives was 25%. The future outcome of our study is promising since early diagnosis and management of high risk family members is possible.
Keyword :
Primary open angle glaucoma, Myocilin, Mutation, Pro370leu.