Comprehensive overview of disease models for Wolfram syndrome: toward effective treatments.

Wolfram syndrome (OMIM 222300) is a rare autosomal recessive disease with a devastating array of symptoms, including diabetes mellitus, optic nerve atrophy, diabetes insipidus, hearing loss, and neurological dysfunction. The discovery of the causative gene, WFS1, has propelled research on this disease. However, a comprehensive understanding of the function of WFS1 remains unknown, making the development of effective treatment a pressing challenge. To bridge these knowledge gaps, disease models for Wolfram syndrome are indispensable, and understanding the characteristics of each model is critical. This review will provide a summary of the current knowledge regarding WFS1 function and offer a comprehensive overview of established disease models for Wolfram syndrome, covering animal models such as mice, rats, flies, and zebrafish, along with induced pluripotent stem cell (iPSC)-derived human cellular models. These models replicate key aspects of Wolfram syndrome, contributing to a deeper understanding of its pathogenesis and providing a platform for discovering potential therapeutic approaches.

Sequential Presentation of Obsessive-Compulsive Disorder and Narcolepsy in a 10-Year-Old Girl With Wolfram Syndrome 1.

ABSTRACT: Wolfram syndrome 1 (WS1) is a rare, autosomal recessive neurodegenerative disorder characterized by diabetes insipidus, insulin-dependent diabetes mellitus, optic atrophy, and deafness resulting from loss-of-function genetic variants in the WFS1 gene. Individuals with WS1 manifest a spectrum of neuropsychiatric disorders. Here, we report a pediatric case of WS1, which stemmed from a novel biallelic WFS1 loss-of-function genetic variant. The individual initially presented with obsessive-compulsive disorder, which was successfully managed by fluvoxamine. After 2 months, the child manifested excessive daytime sleepiness. Clinical evaluation and sleep recordings revealed a diagnosis of narcolepsy type 2. Excessive daytime sleepiness was improved with methylphenidate. To the best of our knowledge, this is the first report of narcolepsy in WS1, which possibly arose during a progressive neurodegenerative process. We emphasize the need for in-depth screening for neuropsychiatric phenotypes and sleep-related disorders in WS1, for clinical management, which significantly improves the quality of life.

[Wolfram-like syndrome: a case report].

Different from classical autosomal recessive Wolfram syndrome, Wolfram-like syndrome is an autosomal dominant disorder caused by a heterozygous mutation in the WFS1 gene. In this case, a 7-year-old male child presented to the eye clinic due to vision loss that could not be corrected, discovered during a routine examination. The child had experienced hearing impairment since early childhood, leading to cochlear implantation. Ophthalmic examination revealed optic disc atrophy in both eyes. Optical coherence tomography imaging demonstrated a distinctive thickening of the outer plexiform layer with abnormal layering, characteristic of a single mutation in the WFS1 gene. Subsequent genetic testing identified a de novo heterozygous missense mutation c.2051C>T (p.A684V) in the WFS1 gene, which ultimately led to the diagnosis of Wolfram-like syndrome.

[Advances in diagnosis and treatment of Wolfram syndrome and related molecular mechanism].

Wolfram syndrome is a rare genetic spectrum disorder characterized by diabetes insipidus, diabetes mellitus, optic atrophy, and deafness, accompanied by other variable clinical manifestations. At present, the prognosis of this syndrome is very poor, the specific molecular mechanism is not clear, effective treatments are lacking to delay, prevent or reverse the development of Wolfram syndrome, and many patients die prematurely due to severe neurological dysfunction. This increases the urgency of the research on the pathogenic molecular mechanism related to Wolfram syndrome and the development of new therapies. This article summarizes the research progress on the pathogenic molecular mechanism and treatment status of Wolfram syndrome, in order to provide reference for the further mechanism research, prevention and treatment of Wolfram syndrome.

[Genetic and prenatal diagnosis of a Chinese pedigree with autosomal recessive Wolfram syndrome 1 due to compound heterozygous variants of WFS1 gene].

OBJECTIVE: To explore the genetic pathogenicity for a Chinese pedigree affected with severe syndromic deafness. METHODS: High-throughput sequencing was carried out to analyze the 415 genes associated with hereditary deafness in the proband who has hearing loss in association with optic atrophy and hyperglycemia. Candidate variants were verified by Sanger sequencing of the proband, her parents and the fetus. RESULTS: The proband was found to harbor compound heterozygous variants of WFS1 gene, namely c.2389G>A (p.Asp797Asn) and c.2345C>T (p.Pro782Leu), which was known to underlie Wolfram syndrome 1. The proband's parents had normal hearing and were both heterozygous carriers for the above variants. The fetus was found to harbor the same compound heterozygous variants and was predicted to have a high risk. CONCLUSION: The compound heterozygous variants of c.2389G>A and c.2345C>T of the WFS1 gene probably underlay the pathogenesis of hearing loss in the proband. Above finding has facilitated genetic counseling and prenatal diagnosis for this family.

[Genetic protocol in primary care for rare diseases: Wolfram syndrome as a prototype]. / Protocolo genético en Atención Primaria para enfermedades raras: el síndrome de Wolfram como prototipo.

Rare diseases, despite their individual low frequency, affect 7% of the population all combined. Consequently, every primary care practitioner (PCP) will have several of these patients under his care. 80% of rare diseases are genetically determined, which makes genetic counseling fundamental in these cases. The follow-up of patients with Wolfram syndrome (WS) can be used to design a protocol to support these patients, with the participation of researchers and healthcare professionals specialized in WS, the patients themselves and their familial environment. This protocol can be suitable for the diagnosis and management of other diseases as well. The main steps of every genetic clinical procedure are developed in this article, emphasizing the role of PCP in supporting patients and their families and in transmitting genetic information in a comprehensible manner.

[Two cases of Wolfram syndrome].

Two adolescents with T1DM participated in the Shanghai Children and Adolescent DM Eye study (SCADE) 2017-2018. The previous T1DM history of the 2 children were 12 years and 4 years respectively. The history of optic atrophy were 8 years and 4 years respectively. The ophthalmic examination showed that there were slight posterior capsule cataract and atrophy of optic atrophy in both patients. Optical Coherance Tomographic examination showed that the choroidal thickness of the inferior inner ring of the optic nerve and RNFL layer thickness decreased markedly, perfusion density and vascular density of the optic disc area and macular decreased markedly, electrophysiological examination showed that amplitude decreased markedly, and visual field examination showed binocular extinction or tubular vision field. Now the 2 adolescents were in closely followed-up. We suggest that children with T1DM whose best corrected visual acuity decreased recently to 0.6 or lower, in addition to routine ophthalmic examination, choroidal thickness, retinal nerve fiber layer thickness, retinal blood flow, ERG and visual field examination are recommended to distinguish wolfram syndrome from T1DM. Genetic sequencing examination of WFS-1 is also recommended if possible.

Wolfram syndrome 1 in the Italian population: genotype-phenotype correlations.

OBJECTIVES: We studied 45 patients with Wolfram syndrome 1 (WS1) to describe their clinical history and to search for possible genotype-phenotype correlations. METHODS: Clinical criteria contributing to WS1 diagnosis were analyzed. The patients were classified into three genotypic classes according to type of detected mutations. RESULTS: WS1 prevalence in Italy is 0.74/1,000,000. All four manifestations of DIDMOAD were found in 46.7% of patients. Differently combined WS1 clinical features were detected in 53.3% of patients. We found 35 WFS1 different mutations and a novel missense mutation, c.1523A>G. WS1 patients were homozygotes or compound heterozygotes for WFS1 mutations except for 2 heterozygote patients (4.5%). Each genotypic group exhibited a different age onset of DM, D, and DI but not of OA. Genotypic Group 2 patients manifested a lower number of clinical manifestations compared to Groups 1 and 3. Moreover, genotypic Group 1 patients tended to have a shorter survival time than the other groups. No differences were found regarding type of clinical pictures. CONCLUSIONS: Our study suggested that molecular WFS1 typing is a useful tool for early assessment of clinical history, follow-up, and prognosis of WS1.

Wolfram syndrome, a rare neurodegenerative disease: from pathogenesis to future treatment perspectives.

BACKGROUND: Wolfram syndrome (WS), a rare genetic disorder, is considered the best prototype of endoplasmic reticulum (ER) diseases. Classical WS features are childhood-onset diabetes mellitus, optic atrophy, deafness, diabetes insipidus, neurological signs, and other abnormalities. Two causative genes (WFS1 and WFS2) have been identified. The transmission of the disease takes place in an autosomal recessive mode but autosomal dominant mutations responsible for WS-related disorders have been described. Prognosis is poor, death occurs at the median age of 39 years with a major cause represented by respiratory failure as a consequence of brain stem atrophy and neurodegeneration. The aim of this narrative review is to focus on etiology, pathogenesis and natural history of WS for an adequate patient management and for the discussion of future therapeutic interventions. MAIN BODY: WS requires a multidisciplinary approach in order to be successfully treated. A prompt diagnosis decreases morbidity and mortality through prevention and treatment of complications. Being a monogenic pathology, WS represents a perfect model to study the mechanisms of ER stress and how this condition leads to cell death, in comparison with other prevalent diseases in which multiple factors interact to produce the disease manifestations. WS is also an important disease prototype to identify drugs and molecules associated with ER homeostasis. Evidence indicates that specific metabolic diseases (type 1 and type 2 diabetes), neurodegenerative diseases, atherosclerosis, inflammatory pathologies and also cancer are closely related to ER dysfunction. CONCLUSIONS: Therapeutic strategies in WS are based on drug repurposing (i.e., investigation of approved drugs for novel therapeutic indications) with the aim to stop the progression of the disease by reducing the endoplasmic reticulum stress. An extensive understanding of WS from pathophysiology to therapy is fundamental and more studies are necessary to better manage this devastating disease and guarantee the patients a better quality of life and longer life expectancy.

Ophthalmologic Manifestations of Wolfram Syndrome: Report of 14 Cases.

PURPOSE: The aim of this study was to describe ophthalmological abnormalities in 14 cases of Wolfram syndrome belonging to 9 different families. METHODS: Patients were submitted to a complete ophthalmological, neurological, otorhinolaryngological, urological, and genetic evaluation. RESULTS: Our sample comprised 14 Caucasian patients belonging to 9 different families. Their ages ranged from 10 to 38 years. The mean duration of known disease was 11.3 ± 8.7 years. Genetic confirmation was obtained in 7 families. There was a parental consanguinity history in 2 families. Five families were homozygous for a mutation of exon 8 of the WFS1 gene (Chr. 4), and 2 patients were heterozygous. Diabetes mellitus was the first manifestation in all except 1 patient. The mean age at diagnosis was 8.7 years (range 3-22). None had diabetic retinopathy. The mean age at diagnosis of optic atrophy was 11.1 years (range 8-35). The best-corrected visual acuity ranged from counting fingers to 20/50. CONCLUSIONS: Association of optic atrophy with insulin-dependent diabetes mellitus should raise the suspicion of Wolfram syndrome.

A novel mutation of WFS1 gene in a Chinese patient with Wolfram syndrome: a case report.

BACKGROUND: 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. CASE PRESENTATION: Here we report a 11-year-old Chinese boy who presented with visual loss, was suspected with optic neuritis (ON) or neuromyelitis optica (NMO) and referred to our department for further diagnosis. Finally he was diagnosed with WS because of diabetes mellitus (DM) and optic atrophy (OA). Eight exons and flanking introns of WFS1 gene were analyzed by sequencing. A novel mutation c.1760G > A in WFS1 gene of exon 8 was identified. CONCLUSION: This report reviews a case of WS associated with a novel mutation, c.1760G > A in WFS1 gene of exon 8, and emphasizes that WS should be taken into account for juveniles with visual loss and diabetes mellitus.

Serum Metabolic Fingerprinting Identified Putatively Annotated Sphinganine Isomer as a Biomarker of Wolfram Syndrome.

Wolfram syndrome (WFS) is an example of a rare neurodegenerative disease with coexisting endocrine symptoms including diabetes mellitus as the first clinical symptom. Treatment of WFS is still only symptomatic and associated with poor prognosis. Potential markers of disease progression that could be useful for possible intervention trials are not available. Metabolomics has potential to identify such markers. In the present study, serum fingerprinting by LC-QTOF-MS was performed in patients with WFS (n = 13) and in patients with T1D (n = 27). On the basis of the obtained results, aminoheptadecanediol (17:0 sphinganine isomer) (+50%, p = 0.02), as the most discriminatory metabolite, was selected for validation. The 17:0 sphinganine isomer level was determined using the LC-QQQ method in the samples from WFS patients at two time points and compared with samples obtained from patients with T1D (n = 24) and healthy controls (n = 24). Validation analysis showed higher 17:0 sphinganine isomer level in patients with WFS compared to patients with T1D (p = 0.0097) and control group (p < 0.0001) with progressive reduction of its level after two-year follow-up period. Patients with WFS show a unique serum metabolic fingerprint, differentiating them from patients with T1D. Sphinganine derivate seems to be a marker of the ongoing process of neurodegeneration in WFS patients.

A novel heterozygous mutation of the WFS1 gene leading to constitutive endoplasmic reticulum stress is the cause of Wolfram syndrome.

BACKGROUND: Wolfram syndrome (WS) is a disorder characterized by the association of insulin-dependent diabetes mellitus (DM), diabetes insipidus, deafness, and optic nerve atrophy. WS is caused by WFS1 mutations encoding WFS1 protein expressed in endoplasmic reticulum (ER). During ER protein synthesis, misfolded and unfolded proteins accumulate, known as "ER stress". This is attenuated by the unfolded protein response (UPR), which recovers and maintains ER functions. Because WFS1 is a UPR component, mutant WFS1 might cause unresolvable ER stress conditions and cell apoptosis, the major causes underlying WS symptoms. We encountered an 11-month-old Japanese female WS patient with insulin-dependent DM, congenital cataract and severe bilateral hearing loss. OBJECTIVE: Analyze the WFS1 and functional consequence of the patient WFS1 in vitro. RESULTS: The patient WFS1 contained a heterozygous 4 amino acid in-frame deletion (p.N325_I328del). Her mutant WFS1 increased GRP78 and ATF6α promoter activities in the absence of thapsigargin, indicating constitutive ER stress and nuclear factor of activated T-cell reporter activity, reflecting elevated cytosolic Ca2+ signals. Mutant transfection into cells reduced mRNA expression levels of sarcoplasmic/endoplasmic reticulum Ca2+ transport ATPase 2b (SERCA2b) compared with wild type. Because SERCA2b is required for ER and cytoplasmic Ca2+ homeostasis, decreased SERCA2b expression might affect ER Ca2+ efflux, causing cell apoptosis. CONCLUSION: A novel heterozygous mutation of WFS1 induced constitutive ER stress through ATF6α activation and ER Ca2+ efflux, resulting in cell apoptosis. These results provide new insights into the roles of WFS1 in UPR and mechanism of monogenic DM.

Diabetes mellitus and optic atrophy: study of the Wolfram syndrome / Diabetes mellitus y atrofia óptica: estudio del síndrome de Wolfram

Background: Wolfram syndrome (WS), also known by the acronym DIDMOAD, is a rare and progresive hereditary disease of autosomal recessive inheritance which minimum ascertainment diagnostic criteria are the occurrence together of diabetes mellitus and optic atrophy before 15 years of age. Objective: To describe the clinical, biochemical and molecular profile of WS in a tertiary care hospital in Mexico. Materials and Methods: We reviewed patients records who fulfill the minimum ascertainment diagnostic criteria of WS presenting between January 1987 and May 2015 in a tertiary care hospital in Mexico. Results: Five patients fulfill the inclusion criteria (three male and two female). Diabetes mellitus was the first manifestation of the syndrome in all of them, with a mean age at diagnosis of 5.8 ± 2.71 years, while the WS diagnosis was established at a mean age of 15.8 ± 8.37 years. All the patients had optic atrophy and two of them presented with the complete DIDMOAD spectrum. We found new associations with autoimmune hepatitis and testicular cancer. Conclusions: This study shows the variability of clinical presentation of WS, as well as two new associations.

Antecedentes: El síndrome de Wolfram (SW), también conocido por el acrónimo DIDMOAD, es una enfermedad hereditaria rara y progresiva, de transmisión autosómica recesiva, cuyos criterios diagnósticos mínimos son diabetes mellitus y atrofia óptica antes de los 15 años de edad. Objetivo: Describir la presentación clínica, bioquímica y molecular del SW en un hospital de tercer nivel en México. Material y Métodos: Se revisaron los expedientes de pacientes que cumplían con criterios diagnósticos clínicos mínimos de SW atendidos entre enero de 1987 y mayo de 2015 en un hospital de tercer nivel en México. Resultados: Cinco pacientes cumplieron con los criterios de inclusión (tres hombres y dos mujeres). La diabetes mellitus fue la primera manifestación del síndrome en todos ellos, con una media de edad al diagnóstico de 5.8 ± 2.71 años, mientras que el diagnóstico del SW se estableció en promedio a los 15.8 ± 8.37 años. Todos los pacientes tenían atrofia óptica y dos presentaron el espectro DIDMOAD completo. Se describen nuevas asociaciones con hepatitis autoinmunitaria y cáncer de testículo. Conclusiones: El presente estudio muestra la variabilidad de presentación clínica del SW y dos asociaciones no descritas previamente.

Wolfram Syndrome: Diagnosis, Management, and Treatment.

Wolfram syndrome is a rare genetic disorder characterized by juvenile-onset diabetes mellitus, diabetes insipidus, optic nerve atrophy, hearing loss, and neurodegeneration. Although there are currently no effective treatments that can delay or reverse the progression of Wolfram syndrome, the use of careful clinical monitoring and supportive care can help relieve the suffering of patients and improve their quality of life. The prognosis of this syndrome is currently poor, and many patients die prematurely with severe neurological disabilities, raising the urgency for developing novel treatments for Wolfram syndrome. In this article, we describe natural history and etiology, provide recommendations for diagnosis and clinical management, and introduce new treatments for Wolfram syndrome.

Mutation update and uncommon phenotypes in a French cohort of 96 patients with WFS1-related disorders.

WFS1 mutations are responsible for Wolfram syndrome (WS) characterized by juvenile-onset diabetes mellitus and optic atrophy, and for low-frequency sensorineural hearing loss (LFSNHL). Our aim was to analyze the French cohort of 96 patients with WFS1-related disorders in order (i) to update clinical and molecular data with 37 novel affected individuals, (ii) to describe uncommon phenotypes and, (iii) to precise the frequency of large-scale rearrangements in WFS1. We performed quantitative polymerase chain reaction (PCR) in 13 patients, carrying only one heterozygous variant, to identify large-scale rearrangements in WFS1. Among the 37 novel patients, 15 carried 15 novel deleterious putative mutations, including one large deletion of 17,444 base pairs. The analysis of the cohort revealed unexpected phenotypes including (i) late-onset symptoms in 13.8% of patients with a probable autosomal recessive transmission; (ii) two siblings with recessive optic atrophy without diabetes mellitus and, (iii) six patients from four families with dominantly-inherited deafness and optic atrophy. We highlight the expanding spectrum of WFS1-related disorders and we show that, even if large deletions are rare events, they have to be searched in patients with classical WS carrying only one WFS1 mutation after sequencing.

High Frequency of Recessive WFS1 Mutations Among Indian Children With Islet Antibody-negative Type 1 Diabetes.

BACKGROUND: While the frequency of islet antibody-negative (idiopathic) type 1 diabetes mellitus (T1DM) is reported to be increased in Indian children, its aetiology has not been studied. We investigated the role of monogenic diabetes in the causation of islet antibody-negative T1DM. METHODS: We conducted a multicenter, prospective, observational study of 169 Indian children (age 1-18 years) with recent-onset T1DM. All were tested for antibodies against GAD65, islet antigen-2, and zinc transporter 8 using validated ELISA. Thirty-four islet antibody-negative children underwent targeted next-generation sequencing for 31 genes implicated in monogenic diabetes using the Illumina platform. All mutations were confirmed by Sanger sequencing. RESULTS: Thirty-five (21%) children were negative for all islet antibodies. Twelve patients (7% of entire cohort, 34% of patients with islet antibody-negative T1DM) were detected to have pathogenic or likely pathogenic genetic variants. The most frequently affected locus was WFS1, with 9 patients (5% of entire cohort, 26% of islet antibody-negative). These included 7 children with homozygous and 1 patient each with a compound heterozygous and heterozygous mutation. Children with Wolfram syndrome 1 (WS) presented with severe insulin-requiring diabetes (including 3 patients with ketoacidosis), but other syndromic manifestations were not detected. In 3 patients, heterozygous mutations in HNF4A, ABCC8, and PTF1A loci were detected. CONCLUSION: Nearly one-quarter of Indian children with islet antibody-negative T1DM had recessive mutations in the WFS1 gene. These patients did not exhibit other features of WS at the time of diagnosis. Testing for monogenic diabetes, especially WS, should be considered in Indian children with antibody-negative T1DM.

An adolescent with Wolfram syndrome and central sleep apnea.

Wolfram syndrome is a rare autosomal recessive disorder affecting approximately 1 in 500,000 individuals. The disorder is most commonly caused by mutations in the WFS1 gene, which encodes an endoplasmic reticulum protein, wolframin, which is thought to protect against endoplasmic reticulum stress-related apoptosis. The major clinical findings of Wolfram syndrome are diabetes mellitus and optic atrophy, both of which usually appear before 16 years of age. Common additional findings include sensorineural hearing impairment, central diabetes insipidus, nonautoimmune hypothyroidism, delayed puberty, neurogenic bladder, cerebellar ataxia, and psychiatric disorders. Central sleep apnea is an uncommon but serious feature of Wolfram syndrome. However, the clinical details of this manifestation have not been documented. Herein, we report an adolescent with recently diagnosed Wolfram syndrome who demonstrated severe central sleep apnea on polysomnography testing. CITATION: Harris JC, Kenkare JD, Schramm CM. An adolescent with Wolfram syndrome and central sleep apnea. J Clin Sleep Med. 2024;20(7):1205-1208.