Retinitis Pigmentosa in the Puerto Rican Population: A Geographic Distribution

Background: Previous studies have reported on retinitis pigmentosa (RP) in Puerto Rico. Information on the geographic distribution of RP mutations in Puerto Rico may lead to higher rates of diagnosis and co-management. We aimed to evaluate whether there are areas with increased incidence of genes leading to RP in the Island. Materials and Methods: We conducted a non-concurrent prospective study on the genotype of 241 patients with RP in Puerto Rico. We evaluated their townships to determine whether there are clusters of genes leading to RP. Genetic studies were done using the Invitae inherited retinal diseases panel analyzing 330 genes. Results: A total of 100 patients were evaluated. Clusters of patients with mutations were found in certain townships. As depicted in the map, a cluster of patients with a mutation in the PDE6B gene was found in San Juan (9), those with the BBS1 gene occurred in San Juan (6) and Bayamon (4), mutations on the USH2A gene were found in Toa Baja (5), mutations in the CRB1 gene appeared in Ciales (4), and mutations in the BBS7 were found in Aibonito (2). Other mutations are scattered throughout the Island. Conclusion: Clusters of mutations were identified in several townships including San Juan, Bayamon, Toa Baja, Ciales, and Aibonito. Some of these are isolated geographically. Additional mutations were identified but only the most pertinent were reported. Genetic studies are warranted in all patients with RP in Puerto Rico. Keywords: retinitis pigmentosa, inherited retinal eye diseases, Usher syndrome, Bardet-Biedl syndrome