Early Diagnosis of Wolfram Syndrome by Ophthalmologic Screening in a Patient with Type 1B Diabetes Mellitus: A Case Report

Wolfram syndrome (WS) is a monogenic diabetes caused by variants of the WFS1 gene. It is characterized by diabetes mellitus (DM) and optic atrophy. Individuals with WS initially present with autoantibody-negative type 1 DM (type 1B DM; T1BDM). The diagnosis is often delayed or misdiagnosed, even after visual impairment becomes apparent. We report a case of WS diagnosed by ophthalmologic screening before the appearance of visual impairment. A 7-year-old male patient developed T1BDM at the age of 3 years. At 6 years of age, his endogenous insulin secretion decreased but was not completely absent, and glycemic control was good with insulin treatment. Fundus examination at that time revealed optic nerve head pallor, and WFS1 gene analysis confirmed a compound heterozygous variant (c.2483delinsGGA/c.1247T>A). Ophthalmological screening can help in early diagnosis of WS in T1BDM, especially when endogenous insulin secretion is preserved, which would facilitate effective treatment.