Mutations in connexin genes and disease

Background: Connexins are a family of transmembrane proteins that are widely expressed in the human body. Connexins play an important role in cell-cell communication and homeostasis in various tissues by forming gap junction channels, which enable a direct passage of ions or metabolites from one cell to another. Twenty-one different connexins are expressed in humans, each having distinct expression patterns and regulation properties. Knowledge on this family of proteins can be gained by making an inventory of mutations and associated diseases in human.

Design: PubMed and other relevant databases were searched. In addition, key review articles were screened for relevant original publications. Sections of representative organs were photographed and annotated.

Results: The crucial role of connexins is highlighted by the discovery of mutations in connexin genes which cause a variety of disorders such as myelin-related diseases, skin disorders, hearing loss, congenital cataract, or more complex syndromes such as the oculodendrodigital dysplasia. This review systematically addresses current knowledge on mutations in connexin genes and disease, focusing on the correlation between genetic defects, cellular phenotypes and clinical manifestations.

Conclusions: The review of diseases caused by mutations in connexin genes highlights the essential nature of connexin function and intercellular communication in tissue homeostasis.