Genetics of punctate palmoplantar keratoderma

Punctate palmoplantar keratoderma (PPPK) is an autosomal-dominant inherited skin disease characterized by progressively worsened hyperkeratotic papules irregularly distributed on the palms and soles. Recent studies have demonstrated that the AAGAB and COL14A1 genes are pathogenic genes of PPPK. In addition, there may be other causative genes for PPPK. So far, a total of 39 AAGAB gene mutations and 1 COL14A1 gene mutation have been reported in families of multiple races and nationalities with PPPK. AAGAB gene mutations can cause functional loss or insufficiency of protein p34, then the impairment of epidermal growth factor receptor (EGFR) recycling and keratinocyte hyperproliferation, and finally lead to the occurrence of PPPK. Studies of the protein function, in vitro cell experiments and repeatability verification tests in other PPPK families are all required to confirm the role of the COL14A1 gene mutation in PPPK. Key words: Keratoderma, palmoplantar; Heredity; Chromosome disorders; Genes; Mutation