Phenotypic and genotypic analysis of <scp><i>SERPINA12</i></scp>‐related autosomal recessive palmoplantar keratoderma in southwestern China

Hereditary palmoplantar keratoderma (hPPK) comprises a clinical and heterogeneous group of skin disorders characterized by hyperkeratosis of the palms and soles. Variants of SERPINA12 have been implicated in autosomal recessive diffuse hPPK, which shares similarities with Nagashima-type PPK due to biallelic variants in SERPINB7. To date, seven SERPINA12 variants have been found in 11 patients with biallelic SERPINA12 variants worldwide. Herein, we described six new cases of hPPK caused by biallelic SERPINA12 variants from southwestern China. Our study showed commonly extensive distribution of skin lesions and various comorbidities in patients with SERPINA12-related hPPK. Moreover, we revealed the variant c.635-7A>G was a founder variant in patients with SERPINA12-related hPPK in southwestern China. Our work is helpful to improve the knowledge of clinical and genetic characteristics of SERPINA12-related hPPK.