Screening for TIGR/myocilin Mutations in Glaucoma Patients From Southern West Haiti

Abstract

Abstract: : Purpose: TIGR/myocilin mutations are associated with 2% to 4% of primary open angle glaucoma (POAG) cases in Caucasians, African-Americans and Asians. The majority of these mutations have been detected in exon 3 of the gene. The aim of this study was to determine whether TIGR/myocilin mutations were also responsible for POAG in the Southern West Haitian population. Methods: TIGR/myocilin exon 3 was screened for mutations in 40 unrelated Haitian POAG patients and in probands from 7 Haitian POAG families showing autosomal dominant (AD) transmission of juvenile or adult-onset POAG. Exon 3 screening was performed by automated DNA sequencing. Results: Among the 47 patients who were screened, two of the sporadic cases carried a TIGR/myocilin mutation. All two patients harbored the same glutamine to lysine substitution at position 352 (Glu352Lys) of the polypeptide. This mutation was also observed in one Haitian living in Quebec. None of the 7 families living in Haiti harbored a TIGR/myocilin mutation. Conclusion: TIGR/myocilin mutations are also associated with POAG in Southern West Haiti. From this small sample, the frequency of TIGR/myocilin mutations was 4.3% in unrelated patients, which is similar to what has been reported in literature for Caucasians, African-Americans and Asians. Further studies are required to determine the prevalence of TIGR/myocilin mutations in the Haitian population and to assess presence of other mutations than Glu352Lys. This would also enable us to determine if there is a founder effect in the Southern West Haitian population.

Keywords: 480 mutations • 420 genetics • 601 trabecular meshwork