Relative frequency of inherited retinal dystrophies in Brazil

Sci Rep. 2018 Oct 29;8(1):15939. doi: 10.1038/s41598-018-34380-0.

Abstract

Among the Brazilian population, the frequency rates of inherited retinal dystrophies and their causative genes are underreported. To increase the knowledge about these dystrophies in our population, we retrospectively studied the medical records of 1,246 Brazilian patients with hereditary retinopathies during 20 years of specialized outpatient clinic care. Of these patients, 559 had undergone at least one genetic test. In this cohort, the most prevalent dystrophies were non-syndromic retinitis pigmentosa (35%), Stargardt disease (21%), Leber congenital amaurosis (9%), and syndromic inherited retinal dystrophies (12%). Most patients had never undergone genetic testing (55%), and among the individuals with molecular test results, 28.4% had negative or inconclusive results compared to 71.6% with a conclusive molecular diagnosis. ABCA4 was the most frequent disease-causing gene, accounting for 20% of the positive cases. Pathogenic variants also occurred frequently in the CEP290, USH2A, CRB1, RPGR, and CHM genes. The relative frequency rates of different inherited retinal dystrophies in Brazil are similar to those found globally. Although mutations in more than 250 genes lead to hereditary retinopathies, only 66 genes were responsible for 70% of the cases, which indicated that smaller and cheaper gene panels can be just as effective and provide more affordable solutions for implementation by the Brazilian public health system.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • ATP-Binding Cassette Transporters / genetics
  • Adaptor Proteins, Signal Transducing / genetics
  • Antigens, Neoplasm / genetics
  • Brazil / epidemiology
  • Cell Cycle Proteins
  • Cytoskeletal Proteins
  • Eye Proteins / genetics
  • Genetic Testing
  • Humans
  • Leber Congenital Amaurosis / diagnosis
  • Leber Congenital Amaurosis / epidemiology
  • Leber Congenital Amaurosis / genetics
  • Macular Degeneration / congenital
  • Macular Degeneration / diagnosis
  • Macular Degeneration / epidemiology
  • Macular Degeneration / genetics
  • Membrane Proteins / genetics
  • Neoplasm Proteins / genetics
  • Nerve Tissue Proteins / genetics
  • Polymorphism, Genetic
  • Prevalence
  • Retinal Dystrophies / diagnosis*
  • Retinal Dystrophies / epidemiology
  • Retinal Dystrophies / genetics
  • Retinitis Pigmentosa / diagnosis
  • Retinitis Pigmentosa / epidemiology
  • Retinitis Pigmentosa / genetics
  • Retrospective Studies
  • Stargardt Disease

Substances

  • ABCA4 protein, human
  • ATP-Binding Cassette Transporters
  • Adaptor Proteins, Signal Transducing
  • Antigens, Neoplasm
  • CHM protein, human
  • CRB1 protein, human
  • Cell Cycle Proteins
  • Cep290 protein, human
  • Cytoskeletal Proteins
  • Eye Proteins
  • Membrane Proteins
  • Neoplasm Proteins
  • Nerve Tissue Proteins
  • RPGR protein, human