WFS1 and diabetes mellitus: Wolfram syndrome 1 gene (WFS1) was identified in the year of 1998 on chromosome 4p16 as a novel gene that causes a rare autosomal recessive neurodegenerative disorder, namely Wolfram syndrome (WFS) (12) alias DIDMOAD syndrome (diabetes insipidus, diabetes mellitus, optic atrophy, and deafness).