Gap junction diseases of the skin

My main focus of research are the Gap junction diseases of the skin. It is an heterogenenic group of heretidary diseases varying from very mild to merily crippling.
Gap junction (GJ) channels are composed of connexin protein subunits, small four-pass transmembrane proteins, and mediate intercellular communication by means of ions and small molecules. Found throughout the animal kingdom, GJ are prominent in tissues requiring rapid intercellular communication including the skin.
Mutations in skin connexins cause diverse phenotypes, illustrating that they must be intimately involved with epidermal growth and differentiation, yet their precise function is unknown. Mutations in connexin26 (Cx26) cause a variety of skin disorders characterized by disturbed proliferation, barrier formation and inflammation. They cause considerable morbidity and even mortality. Cx26 is considered the most important epidermal gap junction protein.
Intriguingly, unlike other skin connexins, Cx26 has an extremely strong genotype-phenotype correlation, even for individual amino acid substitutions. For instance, N14K (single letter amino acid code) is associated with hypotrichosis-deafness syndrome, whereas S17F causes a disorder resembling keratitis-ichthyosis-deafness syndrome (KID). Likewise, N54K causes Bart-Pumphrey syndrome and Y65H/D66H Vohwinkel’s, two disparate skin disorders associated with palmoplantar keratoderma (PPK).

If you are interested in more I suggest to read the following review:

Eugene A. de Zwart-Storm, Patricia E. Martin, Maurice A. M. van Steensel. 2009. Gap junction diseases of the skin – novel insights into their pathogenesis from new mutations. Expert Review of Dermatology. Review, submitted. Click for pubmed