Molecular Genetic Study of Congenital Ichthyosiform Erythroderma (CIE) Reveals a Novel Likely Pathogenic Variant in an Iranian Pedigree

Introduction: Congenital ichthyosiform erythroderma (CIE) is a subtype of autosomal recessive congenital ichthyosis (ARCI), a group of ineffective keratinization disorders, which mainly results from missense mutations in the transglutaminase 1 (TGM1) gene. Case Presentation: Herein, a 9-year-old male case of CIE is presented, for whom we conducted genetic testing to uncover the underlying molecular cause of his condition. We performed whole-exome sequencing (WES) on the DNA extracted from blood, and the data was analyzed for checking pathogenic variants. Analysis of the WES data identified a novel missense variant, c.1165C >T (p. Arg389Cys), in the TGM1 gene. Evaluation of this variant via in silico tools showed its detrimental consequences on the stability and function of the encoded protein. The variant was characterized as likely pathogenic based on the American College of Medical Genetics and Genomics guidelines for variant interpretation. Analysis of all available family members confirmed the co-segregation of this novel variant with the CIE disease within the family. Conclusions: This study reported the successful application of WES and bioinformatics analysis to identify a novel mutation in a well-established ARCI-causing residue in an Iranian patient.