Wolfram syndrome (WS), caused by mutations of the Wolfram syndrome 1 (WFS1) gene on chromosome 4p16.1, is an autosomal recessive disorder characterized by diabetes insipidus (DI), neuro-psychiatric disorders, hearing deficit, and urinary tract anomalies.
The clinical phenotype of WFS2 differs from WFS1 for the absence of diabetes insipidus and psychiatric disorders, and for the presence of bleeding upper intestinal ulcers and defective platelet aggregation.
(i) 15% of published patients do not fulfill the current -inclusion criterion; (ii) genotypic prevalence differences may exist among countries; (iii) diabetes mellitus and optic atrophy might not be the first two clinical features in some patients; (iv) mutations are nonuniformly distributed in WFS1; (v) age at onset of diabetes mellitus, hearing defects, and diabetes insipidus may depend on the patient's genotypic class; and (vi) disease progression rate might depend on genotypic class.
In conclusion, the phenotype associated with this structural rearrangement, which substantially reduces the synthesis of Wolframin, confirms a tissue-specific pattern of expression of WFS1, suggests the presence of a different protein dosage sensitivity in different tissues and could be causative of DI and OA in our patient.
The etiology involves a single gene mutation of the wolframin protein inducing endoplasmic reticulum stress and apoptosis in selected cell types with resultant diabetes insipidus, diabetes mellitus, optic atrophy, and sensory-neural deafness.
The particular radiologic assessment of patients with WFS proofed that, urinary tract dilatation was detected in WFS-1 and WFS-2 patients though all WFS-2 patients have no diabetes insipidus.