Scrutinising the role of simvastatin in a patient of Pachyonychia Congenita with KRT6A gene mutation.

A 25-year-old male patient presented with palmoplantar keratoderma, dystrophic nails, severe plantar pain and oral leukokeratosis since birth. On genetic analysis, a heterozygous KRT6A gene missense mutation (c.1381G > A, p.Glu461Lys in exon 7) was identified by next-generation sequencing technology, consistent with pachyonychia congenita 6a. Oral simvastatin 40 mg was started once daily, and after 16 weeks of therapy, excellent improvement was noted in palmoplantar keratoderma and plantar pain. The maximum thickness of his foot callosity reduced by 4 mm on ultrasonography, and the Dermatology Life Quality Index score dropped significantly by eight points. These benefits may be attributed to inhibition of KRT6A gene expression, modulation of autophagy and mitophagy and Keap1-Nrf2 signalling activation; the latter two mechanisms of statins previously undiscussed in the context of pachyonychia congenita. Simvastatin and other statins are pathogenesis-targeted, disease-modifying therapy in pachyonychia congenita, therefore qualifying as a promising treatment avenue and warranting further clinical trials.