CHM/REP1 transcript expression and loss of visual function in patients affected by choroideremia

Valentina Di Iorio, Gabriella Esposito, Francesca De Falco, Rosa Boccia, Tiziana Fioretti, Raffaella Colucci, Giuseppe De Rosa, Paolo Melillo, Francesco Salvatore, Francesca Simonelli, Francesco Testa

Research output: Contribution to journalArticle

Abstract

PURPOSE. To evaluate the disease progression in patients with clinical and genetic diagnoses of choroideremia during a long-term follow-up and to investigate the relationship between pathogenic variants in the CHM/REP1 gene and disease phenotypes. METHODS. We performed a retrospective longitudinal study on 51 affected men by reviewing medical charts at baseline and follow-up visits to extract the following ocular findings: best-corrected visual acuity, Goldmann visual field, optical coherence tomography, microperimetry. Data obtained from the analysis of DNA and mRNA were reevaluated for genetic classification of patients. RESULTS. The longitudinal analysis showed a significant (P < 0.001) worsening of best-corrected visual acuity with a mean rate of 0.011 logMar per year before 50 years and 0.025 logMar per year after 50 years. Similarly, V4e Goldmann visual field area significantly (P ≤ 0.01) decreased at a mean rate of 2.7% per year before 40 years and 5.7% after 40 years. Moreover, we observed a significant (P < 0.05) decrease of macular sensitivity with a mean rate of 5.0% per year and a decrease of mean macular thickness with a mean rate of 0.8% per year. We classified our patients into two groups according to the expression of the CHM/ REP1 gene transcript and observed that mutations leading to mRNA absence are associated with an earlier best-corrected visual acuity and Goldmann visual field loss. CONCLUSIONS. Our analysis of morphological and functional parameters in choroideremia patients showed a slow disease progression, particularly in the first decades of life. Overall, reevaluation of clinical and molecular data suggests exploring the genotype–phenotype relationship based on CHM/REP1 transcript expression.

Original languageEnglish
Pages (from-to)1547-1555
Number of pages9
JournalInvestigative Ophthalmology and Visual Science
Volume60
Issue number5
DOIs
Publication statusPublished - Apr 2019

Keywords

  • Choroideremia
  • Genotype-phenotype correlation
  • Longitudinal study
  • Visual acuity
  • Visual field

ASJC Scopus subject areas

  • Ophthalmology
  • Sensory Systems
  • Cellular and Molecular Neuroscience

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    Di Iorio, V., Esposito, G., De Falco, F., Boccia, R., Fioretti, T., Colucci, R., De Rosa, G., Melillo, P., Salvatore, F., Simonelli, F., & Testa, F. (2019). CHM/REP1 transcript expression and loss of visual function in patients affected by choroideremia. Investigative Ophthalmology and Visual Science, 60(5), 1547-1555. https://doi.org/10.1167/iovs.18-25501