Cardiomyopathy with alopecia and palmoplantar keratoderma (CAPK) is caused by a JUP mutation

Summary Inherited desmosomal cardiocutaneous syndromes are characterized by the quartet of woolly hair, palmoplantar keratoderma (PPK), skin fragility and cardiac abnormalities, which are caused by mutations in genes coding for desmosomal proteins. We describe a previously unrecognized autosomal recessive syndrome in a family with arrhythmogenic right ventricular cardiomyopathy associated with alopecia and PPK (named CAPK). Genetic investigation of the family led us to find a homozygous disease‐causing mutation, p.R265H, in JUP which encodes plakoglobin, a well‐described member of the desmosome complex. This study expands the clinical spectrum of disorders associated with germline mutations affecting desmosomal proteins by describing a novel phenotype.