Keywords
KRT5 gene
Gene mutation
Submitted : 2026-06-10
Accepted : 2026-06-25
Published : 2026-07-10
Abstract
Background: Epidermolysis bullosa simplex (EBS) with mottled pigmentation (EBS-MP; OMIM 131960) is a rare subtype of EBS that is characterized by blistering, mottled pigmentation, punctate hyperkeratosis, and dystrophic nails. It is predominantly caused by heterozygous gain-of-function mutations in the keratin 5 (KRT5) and keratin 14 (KRT14) genes. Objective: The purpose of this study was to identify the KRT5 and KRT14 gene mutations in a Chinese family affected with EBS-MP and analyze the clinical manifestations. Methods: Whole-exome sequencing (WES) and Sanger sequencing were performed to explore the mutations of an EBS-MP pedigree that included a 24-year-old man and his parents. Results: WES revealed a heterozygous c.74C>T (p.Pro25Leu) mutation in KRT5 in the proband and his mother, which caused the substitution of proline in codon 25 with leucine (p.P25L). The same mutation was not present in the unaffected father. Conclusion: We confirmed the diagnosis of EBS-MP in this family, which was caused by the p.P25L mutation in KRT5. The proband presents additional manifestations, clinical heterogeneity of EBS-MP about skin features is acknowledged. Further observations and studies of EBS-MP are required to confirm or exclude the possible connection.
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