Pachyonychia congenita (PC) is a rare genetic disorder which is inherited in an autosomal dominant pattern. We report a sporadic novel H1 mutation in the KRT6A gene (c. 428G>A/p.Ser143Asn) in a Chinese infant patient. The mutation is concurrent with a single-nucleotide polymorphism and resulted in a serine for asparagine substitution in H1 subdomain of KRT6A chain next to the rod domain. The infant showed the classic symptoms of pachyonychia congenita.
Conclusion: The heterozygous missense mutation c. 428G > A/p.Ser143Asn in KRT6A exon 1 may cause severe disease.