Background: The “autosomal recessive congenital ichthyosis (ARCI)” refers to a group of rare, heterogeneous, and non-syndromic disorders of keratinization, represented as abnormal scales over the entire body and attributable to defective epidermal keratinocyte differentiation and lipid metabolism. ARCI is caused by mutations in a wide variety of genes, including ABCA12, ALOX12B, ALOXE3, CYP4F22, NIPAL4, TGM1, CERS3, PNPLA1, CASP14, SDR9C7, and SULT2B1. The most common cause of ARCI is a TGM1 gene mutation, which is strongly associated with a collodion membrane at birth.
Case presentation: A 15-year-old male patient presented with extensive scaling over the entire body since birth. His history revealed that he was born ash-colored in a membrane, kept in an incubator for one month, and clinically diagnosed with ichthyosis at birth. The patient, who had undergone no previous genetic testing, was subjected to whole exome sequencing with the preliminary diagnosis of autosomal recessive/X-linked recessive congenital ichthyosis. The analysis identified a homozygous c.1020delG change in the TGM1 gene in the form of a frameshift mutation that is classified as pathogenic according to the American College of Medical Genetics criteria.
Conclusion: Next-generation sequencing technologies employing whole-exome sequencing enable the sequencing of all protein-coding DNA regions in a single run.
Key words: Congenital, ichthyosis, TGM1, whole exome sequencing.
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