Mutations in SAM syndrome and palmoplantar keratoderma patients suggest genotype/phenotype correlations in DSG1 mutations

Heterozygous mutations in DSG1, encoding desmoglein 1, result in autosomal dominant striate palmoplantar keratoderma (SPPK). Although SPPK is the predominant feature, the keratoderma is sometimes only focal or diffuse. In contrast, biallelic mutations in DSG1 cause severe dermatitis, multiple allergies, and metabolic wasting (SAM) syndrome. Here, we describe one patient with SAM syndrome and another with diffuse palmoplantar keratoderma (DPPK) due to DSG1 mutations.