Wolfram syndrome 2: a novel CISD2 mutation identified in Italian siblings.

Wolfram syndrome, also referred to as Diabetes Insipidus, Diabetes Mellitus, Optic Atrophy and Deafness (DIDMOAD), is a rare autosomal recessive neurodegenerative disorder. Affected individuals had childhood insulin-requiring non-autoimmune diabetes mellitus and bilateral progressive optic atrophy, usually occurring during the first and second decade of life, respectively. Neurological clinical features include sensorineural hearing loss (slowly progressive high-frequency deafness), ataxia, dementia and psychiatric disease; olfactory defects are also frequent; central apnoea is a common cause of mortality. Further, neuronal degeneration might be involved in gastrointestinal dysmotility and a number of urinary tract dysfunctions (hydroureter, detrusor-sphincter dyssynergia, detrusor overactivity, urinary tract atony).