WFS1: A gene on the short (p) arm of chromosome 4 in band 4p16 that encodes (provides the instructions for) a protein called wolframin. Mutations in WFS1 are associated with Wolfram syndrome and with nonsyndromic deafness (hearing loss without related signs and symptoms affecting other parts of the body).
Wolframin is found in cells throughout the body, with the highest concentrations in the heart, brain, lungs, and pancreas. Wolframin is also present in cells in the inner ear. The function of wolframin is not entirely known. It may play a role in processing proteins and in the survival of nerve cells and cells in the pancreas that make insulin. Insulin controls the amount of the sugar glucose in the blood that is passed into cells for conversion to energy. In the inner ear, wolframin may help maintain the proper levels of charged atoms (ions), which is essential for hearing.
More than 100 WFS1 mutations have been identified in people with Wolfram syndrome (also called DIDMOAD). This syndrome is characterized by type 1 diabetes mellitus (in which there is a lack of insulin), gradual loss of vision due to the wasting away (atrophy) of the nerve that connects the eye to the brain (optic nerve), hearing loss, and other complications that affect the bladder, kidneys, and nervous system during adolescence and young adulthood. Some of these mutations change an amino acid (the building material of proteins) in wolframin, while other mutations delete amino acids from the protein or insert additional ones. These mutations cause a loss of wolframin function because an inactive form of the protein is made or protein production is prevented altogether.
WFS1 mutations have also been identified in individuals with nonsyndromic deafness that is inherited in an autosomal dominant manner. Most of these mutations change a single amino acid (the building material of proteins) in the wolframin protein. One mutation deletes an amino acid from wolframin. Nearly all the mutations affect the same region of the protein (known as the C-terminal domain) and probably alter the structure of wolframin.