Wolfram syndrome is a rare autosomal recessive disorder characterized by diabetes mellitus, optic atrophy, and progressive neurodegeneration, often summarized by the acronym DIDMOAD (diabetes insipidus, diabetes mellitus, optic atrophy, and deafness). We report a 27-year-old male with a history of diabetes mellitus, progressive visual loss leading to blindness, and bilateral sensorineural hearing loss. His family history was notable for diabetes-related mortalities and visual impairment in multiple members of the family. Clinical evaluation showed uncontrolled blood glucose level, optic atrophy, and high-frequency sensorineural hearing loss. A clinical diagnosis of Wolfram syndrome was made using the Euro-Wolfram, Alström, and Bardet-Biedl (WABB) criteria. Wolfram syndrome should be suspected in young patients with early-onset diabetes mellitus and visual or hearing impairment. This case report highlights the role of timely multidisciplinary management in preventing disease-related complications.

Wolfram-like syndrome is an autosomal dominant disorder related to classical autosomal recessive Wolfram syndrome. It is characterized by diabetes mellitus, optic atrophy, and sensorineural hearing loss, but typically presents with milder or incomplete features. These atypical and late-onset forms pose a diagnostic challenge. A 58-year-old male presented with progressive bilateral visual loss, hearing loss, and a history of diabetes mellitus. Optical coherence tomography revealed bilateral optic atrophy, and genetic testing identified a heterozygous pathogenic variant, NM_006005.3:c.409_424dup (p.Val137Glyfs∗110), in the WFS1 gene, confirming the diagnosis of Wolfram-like syndrome. This case highlights the variability in clinical presentation of Wolfram-like syndrome, including unusually late symptom onset. It also emphasizes the role of genetic modifiers and the importance of distinguishing this condition from classical Wolfram syndrome, particularly in adult-onset cases. Early recognition of Wolfram-like syndrome in atypical presentations is critical for appropriate management and patient counseling. The objective of this report is to describe a case of Wolfram-like syndrome with unusually late onset, underline its distinguishing features, and raise awareness of this under-recognized disorder.

Mutations in the WFS1 gene are implicated in Wolfram syndrome (WS), Wolfram-like syndrome (WFLS), and maturity-onset diabetes of the young (MODY). Wolfram syndrome 1 (WFS1) is a diabetes-related gene encoding wolframin, a glycoprotein with nine transmembrane domains localized in the endoplasmic reticulum. However, the relationship between WFS1 mutations and their associated phenotypes remains incompletely understood, requiring additional patient data collection for further investigation. Here we collected and analyzed clinical data from three diabetes pedigrees, and to assess the genotype-phenotype correlation. High-throughput sequencing was employed to detect WFS1 gene mutations, followed by pathogenicity and conservation analysis using bioinformatics software. A three-dimensional wolframin protein structure was constructed to investigate the potential effects of the mutations. Moreover, the distribution of WFS1 mutations and their associated clinical phenotypes were analyzed by summarizing genetic variations of the WFS1 gene recorded in the Human Gene Mutation Database. Four heterozygous WFS1 mutations were identified in three diabetes families. Among these, c.1523_1524del/p.Y508Cfs*34 was identified as a frameshift mutation, while the others were missense mutations. Bioinformatics predictions revealed that c.766A>G/p.K256E is a benign and novel mutation, whereas the remaining mutations were classified as pathogenic. Furthermore, c.985T>A/p.F329I was validated as a MODY-associated mutation within a specific family. A comprehensive summary of all reported WFS1 mutations indicated that mutations associated with WS phenotypes are approximately 18.7 times more frequent than those associated with MODY phenotypes. Missense mutations accounted for the highest proportion of WFS1 mutations associated with different clinical phenotypes, with the majority located in exon 8. This study identified a novel WFS1 mutation, c.766A>G/p.K256E, expanding the known mutation spectrum of the WFS1 gene. The findings suggest that inactivating mutations and benign missense mutations are associated with more severe WS phenotypes compared to purely pathogenic missense mutations. Moreover, c.985T>A/p.F329I was validated as a MODY associated mutation. Finally, by summarizing the genotype-phenotype relationships of WFS1, it is concluded that the WFS1 gene shows a different association with WS, WFSL and MODY.

A heterozygous mutation in the WFS1 gene is responsible for autosomal dominant non-syndromic hearing loss (DFNA6/14/38) and Wolfram-like syndrome, which is characterized by bilateral sensorineural hearing loss with optic atrophy and/or diabetes mellitus. However, detailed clinical features for the patients with the heterozygous p.A684V variant remain unknown. We report the clinical details of 14 cases with a heterozygous p.A684V variant in the WFS1 gene identified from target resequencing analysis of 63 previously reported deafness genes by next-generation sequencing of 15,684 hearing loss patients (mean age 27.5 ± 23.1 years old, 6574 male, 8612 female and 498 for whom information was unavailable). Among the 14 patients from 13 families with the p.A684V variant, nine were sporadic cases. In addition, we confirmed de novo occurrence of this variant in seven families. This result strongly supports the notion that this variant was located on a mutational hotspot. When comparing previously reported cases of autosomal dominant WFS1 gene-associated hearing loss, most of the patients in this study showed severe-to-profound bilateral sensorineural hearing loss (genotype-phenotype correlation). Two patients had optic atrophy, while the others did not have any other complications. The identified heterozygous p.A684V variant appears to be a hotspot mutation and likely to cause severe-to-profound hearing loss in early childhood. Cochlear implantation is considered favorable in cases of hearing impairment due to this variant.

Wolfram syndrome due to bi-allelic variants in WFS1 and mono-allelic Wolfram-like syndrome have variable ocular and syndromic associations. In this report, eight patients are described. A retrospective observational case series with detailed ophthalmic and systemic phenotyping, optical coherence tomography (OCT), and neuroimaging. Molecular investigations included gene panel and targeted Sanger sequencing. Eight patients (six female, two male) from six families were diagnosed with optic atrophy at a mean age of 15.5 ± 6.2 years (range 8-23) with mean follow-up of 3.2 ± 3.4 years (range 1.5-12.1). Three were asymptomatic. Mean presenting visual acuity was 0.31 ± 0.26 logMAR (Snellen equivalent 20/40). Diabetes mellitus was present in five patients (detected after screening in one), sensorineural hearing loss in five and diabetes insipidus in one. Other systemic features included psychiatric disorders in four patients and bladder dysfunction in three patients. OCT demonstrated marked nerve fiber layer loss in all patients. In dominant disease, macular OCT demonstrated a linear splitting abnormality of the outer plexiform layer (OPL) not found in recessive disease. Three novel variants in WFS1 were identified. After identification of the p.Val606Gly variant in three Māori patients including one with cone-rod retinal dystrophy, a reference database of 80 Māori/Pasifika patients with retinal dystrophy/optic atrophy was interrogated. This identified the variant in 10 patients with disease attributed to other genes. In Wolfram syndrome, systemic features are variable. Pathognomonic OPL lamination is associated with dominant disease. Early recognition of potentially syndromic optic atrophy allows prompt diagnosis of unrecognized diabetes mellitus.