Original articleFrequency and Clinical Pattern of Vitelliform Macular Dystrophy Caused by Mutations of Interphotoreceptor Matrix IMPG1 and IMPG2 Genes
Section snippets
Methods
The DNA repository of the Maolya Outpatient Clinic for Genetic Sensory Diseases (Montpellier University Hospital, Montpellier, France) was screened for families with vitelliform macular dystrophy. Informed consent was obtained for clinical examination and genetic analysis from all patients in agreement with the principles of the Declaration of Helsinki. We also obtained ethical approval from the Montpellier University Hospital.
Results
Seventy-six families had a vitelliform dystrophy. Among the 45 families with an age of onset before 40 years, 24 had a mutation in BEST1, and among the 31 families with an age of onset older than 40 years, 3 had a mutation in PRPH2. For the 49 families without identified mutations, 3 families were found to have a mutation in IMPG1 (6% of included families, 11 patients; Fig 1, available at www.aaojournal.org) and 1 family was found to have a mutation in IMPG2 (2% of included families, 2
Discussion
The aim of the present study was to evaluate the frequency and the relevant clinical and SD-OCT findings of IMPG1 and IMPG2 vitelliform dystrophies in patients for whom exonic mutations or rearrangements in BEST1 and PRPH2 had been excluded. It should be pointed out that deep intronic mutations were not screened. IMPG1 was associated more frequently with such a phenotype in comparison with IMPG2. Nevertheless, these 2 genes account for a small proportion of cases: 4 families among the 49
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2022, Stem Cell ReportsCitation Excerpt :These post-translational modifications (PTMs) are believed to be important for binding other IPM constituents, stabilizing the matrix, and supporting the growth and maintenance of OS (Chen et al., 2004). Mutations in IMPG2 cause multiple retinal pathologies, including a severe form of autosomal recessive RP that also affects the cone photoreceptor-rich macula early in the course of the disease, leading to irreversible vision loss in childhood (Bandah-Rozenfeld et al., 2010; Bocquet et al., 2013; Brandl et al., 2017; Huet et al., 2014; Khan and Al Teneiji, 2019; Meunier et al., 2014). Structurally, noninvasive imaging of affected patients by optical coherence tomography shows a reduction in retinal thickness and a loss of outer retinal bands corresponding to the photoreceptor OS layer (Brandl et al., 2017; Khan and Al Teneiji, 2019).
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Financial Disclosure(s): The author(s) have no proprietary or commercial interest in any materials discussed in this article.