Background: Pachyonychia congenita (PC) is a rare, autosomal dominant genodermatosis characterized by palmoplantar keratoderma, nail dystrophy, cystic lesions, follicular hyperkeratosis, mucosal leukokeratoses, hyperhidrosis, hoarseness, and, rarely, natal teeth. Five keratin genes, KRT6A, KRT6B, KRT6C, KRT16  and KRT17 , have been found to be associated with PC.
Methods: Using polymerase chain reaction and Sanger sequencing techniques, the purpose of the present study was to investigate the clinical features associated with PC and discover disease-associated variants. The KRT6A, KRT16, KRT17 , and KRT6B  exonic and flanking region sequences were amplified and directly sequenced to detect mutations.
Results: Across two independent instances of PC, we identified a previously reported c.1393T>C (p.Tyr465His) mutation in exon 7 of KRT6A , and a novel c.1237G>C (p.Glu413Gln) heterozygous missense mutation in exon 6 of the KRT16  gene.
Conclusion: Through phenotype-genotype analysis among PC pedigrees, confirmed diagnoses of PC-K6a and PC-K16 were made in the two patients who presented with symptoms of PC. A new pathogenic mutation site in PC-K16 was potentially discovered.
Keywords: KRT6A  gene, KRT16  gene, pachyonychia congenital, phenotype-genotype