This is a very rare syndrome, its main characteristic being central diabetes insipidus. This is a situation where the posterior pituitary gland does not produce vasopressin, a hormone that promotes the reabsorption of water by the kidney. In its absence, patients urinate large amounts very frequently, disturbing their fluid balance. This causes them to drink excessively. In Wolfram syndrome, diabetes insipidus is associated with diabetes mellitus type 1, atrophy of the optic nerves and deafness. Very little is known of the cause or pathophysiology of this condition.