I-Tracking Neurodegeneration in Early Wolfram Syndrome

Study Summary

Wolfram syndrome (WFS; OMIM #222300) is a rare autosomal recessive disease clinically defined in 1938 as the combination of childhood-onset insulin dependent diabetes, optic nerve atrophy, diabetes insipidus and deafness. Based on early descriptions, neurological features were thought to appear later in the disease with death occurring in middle adulthood. Importantly, the major causative gene (WFS1) was identified in 1998. This discovery allowed researchers to determine that the WFS1 gene encodes the protein wolframin, which helps protect cells from endoplasmic reticulum (ER) stress-mediated apoptosis, potentially via intracellular calcium homeostasis. Pathogenic mutations in WFS1 can result in death or dysfunction of cells that are under high ER stress, such as insulin-producing pancreatic β cells, causing insulin dependent diabetes. In addition, knowing the causative gene has allowed researchers to identify patients by their WFS1 mutation rather than the classic set of symptoms, leading to the increasing realization that the WFS1-related phenotype (including neurologic symptoms) is much more variable than previously understood. The first iteration of this grant (HD070855 "Tracking Neurodegeneration in Early Wolfram Syndrome") contributed to this shift in understanding. In this time, the research team has built a successful annual research clinic for WFS, that has met or exceeded recruitment goals for patients and controls, validated a clinical severity rating scale for WFS, described an unexpectedly early neurophenotype of reduced balance, smell identification and ventral pons volume, identified alterations in traditional diffusion tensor imaging (DTI) metrics that suggest hypomyelination as a pervasive neuropathological feature of WFS and provided justification for the selection of two primary outcomes (visual acuity and ventral pons volume) in a newly funded clinical efficacy study in WFS (Barrett, PI).