WFS1 and Wolfram syndrome: Mutation analysis of WFS1 in families with DFNA6/14 revealed that the identified pathogenic mutations in this disorder tend to be non-inactivating and cluster at the C-terminus or N-terminus of the protein domain [34], [35], whereas most of the pathogenic mutations in Wolfram syndrome patients are distributed over the entire coding region and are often inactivating mutations resulting in loss of function of the encoded protein [36].