Potential digenic inheritance of SERPINB7 and SERPINA12 variants in Chinese patients with Nagashima-type palmoplantar keratosis

Nagashima-type palmoplantar keratosis, caused by biallelic loss-of-function variants in SERPINB7, is the most prevalent palmoplantar keratoderma in East Asia and manifests as diffuse palmoplantar erythema and hyperkeratosis. We report four different variants of SERPINA12 in six Chinese individuals and identified the recurrent variant c.970_971del as a founder variant among East Asians.