RESUMEN
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 Bayamón (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, Bayamón, 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.
RESUMEN
BACKGROUND: Retinitis pigmentosa (RP) is a genetically heterogeneous group of diseases characterized by complete progressive vision loss; it has a prevalence of approximately one in 2500-7000. Patients with RP may have isolated findings, or the disorder can occur as part of a constellation of other abnormalities that, together, are known as syndromic RP. The aim of this study was to describe the results of a genetic analysis of a cohort of Puerto Ricans with a clinical diagnosis of RP. MATERIALS AND METHODS: This was a cross-sectional study with a cohort of 224 Puerto Rican patients who carried a clinical diagnosis of RP. During a local (Puerto Rico) RP convention, the patients were offered genetic analysis. Volunteering patients signed consent forms for the study. Saliva samples were obtained and analyzed. Patients were evaluated by at least one of the authors. Patients with pathogenic mutation(s), according to the panel, were classified as positive and sorted based on the results. RESULTS: Of 224 patients, 161 (71.9%) had pathogenic gene variants associated with IRDs. 54.5% (122/224) of cases were conclusive. More than half (72/122) of these cases are explained by mutations in the BBS1, PDE6B, CNGB1, and USH2A genes. Genetic analysis showed that the highest rate of pathogenic variants in our cohort was found in the BBS1 gene. CONCLUSIONS: This was the first genetic analysis in Puerto Rico of patients with RP. The most common mutation associated with RP was found in the BBS1 gene. The frequency of other pathogenic variants related to RP in Puerto Rico were different to those reported in Spain.
