Novel mutation in the TGFBI gene in a Moroccan family with atypical corneal dystrophy
Abstract Background: Corneal dystrophies (CDs) are a heterogeneous group of bilateral, genetically determined, non-inflammatory bilateral corneal diseases which are usually limited to the cornea. CD is characterized by a large variability in the age of onset, evolution and visual impact and the accumulation of insoluble deposits at different depths of the cornea. Clinical symptoms revealed bilaterally multiple superficial, epithelial, and stromal anterior granular opacities, in different stages of severity among three patients of this family. 99 genes are involved in CDs.The aim of this study is to identify pathogenic variant caused atypical corneal dystrophy in a large Moroccan family and to describe the clinical phenotype with their severe different stages of evolution.Methods: In this study, we report a large Moroccan family with CD. Whole Exome Sequencing (WES) was performed in the three affected members who shared a phenotype of a corneal dystrophy in different stages of severity. De variant validation and familial segregation were done by Sanger sequencing in affected sister and mothers and in two unaffected brothers.Results: Whole exome sequencing showed a novel heterozygous mutation (c.1772C>A; p.Ser591Tyr) in TGFBI gene. Clinical examinations demonstrated bilaterally multiple superficial, epithelial and stromal anterior granular opacities; in different stages of severity among three patients of this family. Conclusions: This report presents a novel mutation in TGFBI gene, found in three family members affected with different phenotypic aspects. This mutation is associated with Thiel-Behnke corneal dystrophy and therefore, it could be considered as a novel phenotype genotype correlation, which will help in genetic counseling for this family