A Novel Large Deletion in the EVER1 Gene in a Family With Epidermodysplasia Verruciformis From India.

Abstract

Epidermodysplasia verruciformis (EV) is a rare autosomal recessive genodermatosis due to mutations in EVER1 and EVER2 genes. The genetic profile of Indian patients with EV has not been previously studied. This report describes the clinical presentation and molecular analysis of a family with EV. Using genomic DNA from two affected probands and healthy controls (two other siblings), conventional polymerase chain reaction (PCR) was conducted with novel primer sets designed to amplify the coding and splice-site regions in the genes EVER1 and EVER 2. This revealed no amplification with a primer set for exons 16 to 18 in the EVER1 gene of both the probands. Subsequently, long-range PCR spanning the length of exon 15-20 and next-generation sequencing demonstrated a homozygous deletion of 2078 bp in the EVER1 gene (EVER1:c.2072_2278del). Screening the family revealed the same homozygous deletion (similar to index cases) in two other affected siblings. The parents and two asymptomatic siblings were heterozygous carriers for the deletion while one healthy sibling was negative. These results were validated with Sanger sequencing. This deletion in exons 17 and 18 of the EVER1 gene results in a frameshift, followed by a premature termination resulting in a severe phenotype. The identification and validation of this large deletion was detected using stepwise amplicon-based target enrichment and long-range PCR, respectively. In this family, this simple strategy greatly enhanced genetic counseling as well as early genetic diagnosis and screening. However, functional assays and larger studies are required to characterize and validate the genetic diversity among Indians with EV.