Paediatric Wolfram syndrome Type 1: should gonadal dysfunction be part of the diagnostic criteria?

Aims: Wolfram Syndrome Spectrum Disorder (WFS1-SD), in its "classic" form, is a rare autosomal recessive disease with poor prognosis and wide phenotypic spectrum. Insulin dependent diabetes mellitus (DM), optic atrophy (OA) diabetes insipidus (DI) and sensorineural deafness (D) are the main features of WFS1-SD. Gonadal dysfunction (GD) has been described mainly in adults with variable prevalence and referred to as a minor clinical feature. This is the first case series investigating gonadal function in a small cohort of paediatric patients affected by WFS1-SD. Methods: Gonadal function was investigated in eight patients (3 male and 5 female) between 3 and 16 years of age. Seven patients have been diagnosed with classic WFS1-SD and one with non-classic WFS1-SD. Gonadotropin and sex hormone levels were monitored, as well as markers of gonadal reserve (inhibin-B and anti-Mullerian hormone). Pubertal progression was assessed according to Tanner staging. Results: Primary hypogonadism was diagnosed in 50% of patients (n=4), more specifically 67% (n=2) of males and 40% of females (n=2). Pubertal delay was observed in one female patient. These data confirm that gonadal dysfunction may be a frequent and underdiagnosed clinical feature in WFS1-SD. Conclusions: GD may represent a frequent and earlier than previously described feature in WFS1-SD with repercussions on morbidity and quality of life. Consequently, we suggest that GD should be included amongst clinical diagnostic criteria for WFS1-SD, as has already been proposed for urinary dysfunction. Considering the heterogeneous and elusive presentation of WFS1-SD, this clinical feature may assist in an earlier diagnosis and timely follow-up and care of treatable associated diseases (i.e. insulin and sex hormone replacement) in these young patients.

Clinical management and obstetric outcome in WFS1 Wolfram syndrome spectrum disorder: A case report and literature review.

OBJECTIVE: Wolfram Syndrome (WS) is a rare autosomal recessive neurodegenerative disorder caused by mutations in WFS1 or CISD2 (WFS2). We present a rare case report of pregnancy with WFS1 spectrum disorder (WFS1-SD) in our hospital and reviewed literature to provide the management of pregnancy in these patients through multi-disciplinary cooperation. CASE REPORT: A 31-year-old (gravida 6, para 1) woman with WFS1-SD conceived naturally. During the pregnancy, she adjusted insulin intermittently to control blood glucose and monitored intraocular pressure changes under the guidance of doctors without any complications. Cesarean section was delivered at 37+4 weeks of gestation due to breech position and uterine scar and the neonatal weight was 3200 g. Apgar score 10 at 1 min, 10 at 5-min and 10 at 10 min, respectively. This rare case had a good maternal and infant outcome under multidisciplinary management. CONCLUSION: WS is an extremely rare disease. Limited information is available on the impact and management of WS on maternal physiologic adaptation and fetal outcome. This case provide a guide for clinicians to raise awareness of this rare disease and strengthen the management of pregnancy in these patients.

WFS1 autosomal dominant variants linked with hearing loss: update on structural analysis and cochlear implant outcome.

BACKGROUND: Wolfram syndrome type 1 gene (WFS1), which encodes a transmembrane structural protein (wolframin), is essential for several biological processes, including proper inner ear function. Unlike the recessively inherited Wolfram syndrome, WFS1 heterozygous variants cause DFNA6/14/38 and wolfram-like syndrome, characterized by autosomal dominant nonsyndromic hearing loss, optic atrophy, and diabetes mellitus. Here, we identified two WFS1 heterozygous variants in three DFNA6/14/38 families using exome sequencing. We reveal the pathogenicity of the WFS1 variants based on three-dimensional (3D) modeling and structural analysis. Furthermore, we present cochlear implantation (CI) outcomes in WFS1-associated DFNA6/14/38 and suggest a genotype-phenotype correlation based on our results and a systematic review. METHODS: We performed molecular genetic test and evaluated clinical phenotypes of three WFS1-associated DFNA6/14/38 families. A putative WFS1-NCS1 interaction model was generated, and the impacts of WFS1 variants on stability were predicted by comparing intramolecular interactions. A total of 62 WFS1 variants associated with DFNA6/14/38 were included in a systematic review. RESULTS: One variant is a known mutational hotspot variant in the endoplasmic reticulum (ER)-luminal domain WFS1(NM_006005.3) (c.2051 C > T:p.Ala684Val), and the other is a novel frameshift variant in transmembrane domain 6 (c.1544_1545insA:p.Phe515LeufsTer28). The two variants were pathogenic, based on the ACMG/AMP guidelines. Three-dimensional modeling and structural analysis show that non-polar, hydrophobic substitution of Ala684 (p.Ala684Val) destabilizes the alpha helix and contributes to the loss of WFS1-NCS1 interaction. Also, the p.Phe515LeufsTer28 variant truncates transmembrane domain 7-9 and the ER-luminal domain, possibly impairing membrane localization and C-terminal signal transduction. The systematic review demonstrates favorable outcomes of CI. Remarkably, p.Ala684Val in WFS1 is associated with early-onset severe-to-profound deafness, revealing a strong candidate variant for CI. CONCLUSIONS: We expanded the genotypic spectrum of WFS1 heterozygous variants underlying DFNA6/14/38 and revealed the pathogenicity of mutant WFS1, providing a theoretical basis for WFS1-NCS1 interactions. We presented a range of phenotypic traits for WFS1 heterozygous variants and demonstrated favorable functional CI outcomes, proposing p.Ala684Val a strong potential marker for CI candidates.

Wolfram syndrome in a young woman with associated hypergonadotropic hypogonadism - A case report.

OBJECTIVES: Wolfram syndrome (WFS) is a rare neurodegenerative disease. Clinical diagnosis is made when nonautoimmune insulin-dependent diabetes is found to be associated with bilateral optic atrophy in a patient early in life. Frequent associations include diabetes insipidus, diabetes mellitus, optic atrophy and deafness. Many other multisystemic associations have been described including menstrual irregularities in female and hypogonadism in male patients. CASE PRESENTATION: We present a first case of WFS associated with hypergonadotropic hypogonadism in a female adolescent diagnosed with WFS both clinically and genetically. Other causes of premature ovarian insufficiency (POI) have been excluded. CONCLUSIONS: This case report shows the importance of gonadal function assessment and follow-up in time for both genders.

Neuro-ophthalmological manifestations of Wolfram syndrome: Case series and review of the literature.

Wolfram Syndrome (WS) is a rare progressive hereditary neurodegenerative disease with hallmark features of diabetes mellitus, optic atrophy, and hearing loss. Its other clinical manifestations may include diabetes insipidus, urological, neurological, and psychiatric abnormalities. We review systemic and ocular manifestations of WS as well as its pathophysiology, diagnostic approach, and treatment options. We then describe a case series of 5 patients (ages 15-38, 60% male) with WS. All had significant progressive visual loss. 3/5 patients had type 1 DM and 4/5 had hearing loss. Other neuro-ophthalmological findings included convergence impairment and end-gaze nystagmus. This case series highlights the variability in clinical presentations of patients with WS, reminding clinicians to maintain high suspicion for this diagnosis in order to allow for prompt diagnosis and genetic counselling for patients and their families.

Longitudinal progression of diabetes mellitus in Wolfram syndrome: The Washington University Wolfram Research Clinic experience.

OBJECTIVE: (1) Describe the progression of diabetes mellitus over time in an observational study of Wolfram syndrome, a rare, genetic, neurodegenerative disorder, which often includes diabetes mellitus and is typically diagnosed during childhood or adolescence. (2) Determine whether C-peptide could be used as a marker of diabetes progression in interventional trials for Wolfram syndrome. METHODS: N = 44 (25F/19M) participants with genetically confirmed Wolfram syndrome attended the Washington University Wolfram Research Clinic annually from 2010 to 2019. Medical history, physical examinations, blood sampling, and questionnaires were used to collect data about diabetes mellitus and other components of Wolfram syndrome. Beta-cell function was assessed by determination of C-peptide during a mixed meal tolerance test. Random coefficients models evaluated the rate of progression of C-peptide over time, and power analyses were used to estimate the number of subjects needed to detect a change in C-peptide decline during an intervention trial. RESULTS: 93.2% of patients had diabetes mellitus. Mean HbA1c across all study visits was 7.9%. C-peptide significantly decreased with increasing duration of diabetes mellitus (p < 0.0001); an optimal break point in C-peptide decline was identified to occur between 0.1 and 2.3 years after diabetes mellitus diagnosis. Twenty patients per group (active vs. control) were estimated to be needed to detect a 60% slowing of C-peptide decline during the first 2.3 years following diabetes diagnosis. CONCLUSION: C-peptide declines over time in Wolfram syndrome and could potentially be used as a marker of diabetes progression in interventional studies for Wolfram syndrome, especially within the first 2 years after diabetes diagnosis.

Early Intervention and Lifelong Treatment with GLP1 Receptor Agonist Liraglutide in a Wolfram Syndrome Rat Model with an Emphasis on Visual Neurodegeneration, Sensorineural Hearing Loss and Diabetic Phenotype.

Wolfram syndrome (WS), also known as a DIDMOAD (diabetes insipidus, early-onset diabetes mellitus, optic nerve atrophy and deafness) is a rare autosomal disorder caused by mutations in the Wolframin1 (WFS1) gene. Previous studies have revealed that glucagon-like peptide-1 receptor agonist (GLP1 RA) are effective in delaying and restoring blood glucose control in WS animal models and patients. The GLP1 RA liraglutide has also been shown to have neuroprotective properties in aged WS rats. WS is an early-onset, chronic condition. Therefore, early diagnosis and lifelong pharmacological treatment is the best solution to control disease progression. Hence, the aim of this study was to evaluate the efficacy of the long-term liraglutide treatment on the progression of WS symptoms. For this purpose, 2-month-old WS rats were treated with liraglutide up to the age of 18 months and changes in diabetes markers, visual acuity, and hearing sensitivity were monitored over the course of the treatment period. We found that treatment with liraglutide delayed the onset of diabetes and protected against vision loss in a rat model of WS. Therefore, early diagnosis and prophylactic treatment with the liraglutide may also prove to be a promising treatment option for WS patients by increasing the quality of life.

Wolfram-like syndrome with bicuspid aortic valve due to a homozygous missense variant in CDK13.

BACKGROUND: Wolfram syndrome (WFS) is characterized by deafness, diabetes mellitus, and diabetes insipidus along with optic atrophy. WFS has an autosomal recessive mode of inheritance and is due to variants in WFS1 and CISD2. METHODS: We evaluated the underlying molecular etiology of three affected members of a consanguineous family with hearing impairment, bicuspid aortic valve, diabetes mellitus and insipidus, clinodactyly, and gastrointestinal tract abnormalities via exome sequencing approach. We correlated clinical and imaging data with the genetic findings and their associated phenotypes. RESULTS: We identified a homozygous missense variant p.(Asn1097Lys) in CDK13, a gene previously associated with autosomal dominant congenital heart defects, dysmorphic facial features, clinodactyly, gastrointestinal tract abnormalities, intellectual developmental disorder, and seizures with variable phenotypic features. CONCLUSION: We report a homozygous variant in CDK13 and suggest that this gene causes an autosomal recessive disorder with hearing impairment, bicuspid aortic valve, diabetes mellitus and insipidus, clinodactyly, and gastrointestinal tract abnormalities.

Autosomal-dominant WFS1-related disorder-Report of a novel WFS1 variant and review of the phenotypic spectrum of autosomal recessive and dominant forms.

Wolfram syndrome was initially reported as an autosomal recessive (AR), progressive neurodegenerative disorder that leads to diabetes insipidus, childhood onset diabetes mellitus (DM), optic atrophy, and deafness (D) also known as DIDMOAD. However, heterozygous dominant pathogenic variants in Wolfram syndrome type 1 (WFS1) may lead to distinct, allelic conditions, described as isolated sensorineural hearing loss (SNHL), syndromic SNHL, congenital cataracts, or early onset DM. We report a family with a novel dominant, likely pathogenic variant in WFS1 (NM_006005.3) c.2605_2616del12 (p.Ser869_His872del), resulting in cataracts, SNHL, and DM in a female and her mother. A maternal aunt had cataracts, DM, and SNHL but was not tested for the familial WFS1 mutation. Both the mother and maternal aunt had early menopause by age 43 years and infertility which may be a coincidental finding that has not been associated with autosomal dominant AD WFS1-related disorder to the best of our knowledge. Screening at risk individuals in families with the AR Wolfram syndrome, for DM, SNHL, and for cataracts is indicated.

Corneal Abnormalities Are Novel Clinical Feature in Wolfram Syndrome.

PURPOSE: To evaluate corneal morphology among patients with Wolfram syndrome (WFS). DESIGN: Comparative observational longitudinal case series of WFS patients with a laboratory approach in the WFS1 gene knockout (Wfs1KO) mouse model. METHODS: A group of 12 patients with biallelic mutations in the WFS1 gene recruited from the whole country and a control group composed of 30 individuals with type 1 diabetes (T1D) were evaluated in a national reference center for monogenic diabetes. All subjects (n = 42) underwent a complete ophthalmic examination, computer videokeratography, and corneal thickness and endothelial measurements. Additionally, WFS patients (n = 9) underwent longitudinal videokeratography and Pentacam evaluation. Corneal characteristics were assessed and compared between both groups. Human and mouse corneas were subjected to immunohistochemistry to detect wolframin expression and microscopic evaluation to study corneal morphology ex vivo. RESULTS: Clinical and topographic abnormalities similar to keratoconus were observed in 14 eyes (58.3%) of 8 WFS patients (66.7%). Flat keratometry, inferior-superior dioptric asymmetry, skewed radial axis, logarithm of keratoconus percentage index, index of surface variance, index of vertical asymmetry, keratoconus index, central keratoconus index, index of height asymmetry, and index of height decentration differed between WFS and T1D patients. Immunohistochemistry demonstrated wolframin expression in human and mouse corneas. Compared with Wfs1WT mice, Wfs1KO mice also presented corneal abnormalities. CONCLUSIONS: Patients with WFS present a high prevalence of changes in corneal morphology compatible with the diagnosis of early stages of keratoconus. Observations in a mouse model suggest that a mutation in the WFS1 gene may be responsible for corneal abnormalities similar to keratoconus.

Clinical and genetic analysis of two wolfram syndrome families with high occurrence of wolfram syndrome and diabetes type II: a case report.

BACKGROUND: Mutations of the WFS1 gene are responsible for most cases of Wolfram syndrome (WS), a rare, recessively inherited neurodegenerative disorder characterized by juvenile-onset non-autoimmune diabetes mellitus and optic atrophy. Variants of WFS1 are also associated with non-syndromic hearing loss and type-2 diabetes mellitus (T2DM). Our study adds to literature significant associations between WS and T2DM. CASE PRESENTATION: In this study, we analyzed the clinical and genetic data of two families with high prevalence of WS and T2DM. Genetic linkage analysis and DNA sequencing were exploited to identify pathogenic variants. One novel pathogenic variant (c.2243-2244insC) and one known pathogenic (c.1232_1233delCT) (frameshift) variant were identified in exon eight of WFS1 gene. CONCLUSIONS: The mutational and phenotypic spectrum of WS is broadened by our report of novel WFS1 mutation. Our results reveal the value of molecular analysis of WFS1 in the improvement of clinical diagnostics for WS. This study also confirms the role of WFS1 in T2DM.

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.

Evidence of retinal degeneration in Wolfram syndrome.

PURPOSE: Wolfram syndrome is characterized by early onset diabetes mellitus, diabetes insipidus, deafness, and optic atrophy, but retinal degeneration has not been described as a major component of the phenotype. We present two cases with Wolfram syndrome and evidence of retinal degeneration. MATERIALS AND METHODS: Observational case series. Patients underwent complete ocular examinations as well as retinal imaging and electroretinography. RESULTS: Both patients had electroretinographic evidence of retinal dysfunction/degeneration in addition to optic atrophy with an otherwise normal-appearing retina. CONCLUSIONS: Some patients with Wolfram syndrome have a mild retinal degeneration that may be a manifestation of the neuronal involvement that is present in this condition.

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 case of young diabetes and parasuicide.

Wolfram syndrome is a rare monogenic cause of juvenile onset diabetes mellitus. It is a non-autoimmune, insulin-deficient state with concurrent or consequent optic atrophy. Here we depict the case of a 16-year-old young girl afflicted with this condition, who presented with parasuicide on a background of depressive disorder. The aetiology of this presentation was attributable to multiple physical ailments and a genetic predisposition conferred by the disease-causing mutation for which she tested positive. She was managed with intensive insulin therapy and specific psychotherapy. Her case highlights the importance of recognising and addressing these comorbidities associated with Wolfram syndrome, so as to curtail disastrous consequences.

Preventive treatment with liraglutide protects against development of glucose intolerance in a rat model of Wolfram syndrome.

Wolfram syndrome (WS) is a rare autosomal recessive disorder caused by mutations in the WFS1 (Wolframin1) gene. The syndrome first manifests as diabetes mellitus, followed by optic nerve atrophy, deafness, and neurodegeneration. The underlying mechanism is believed to be a dysregulation of endoplasmic reticulum (ER) stress response, which ultimately leads to cellular death. Treatment with glucagon-like peptide-1 (GLP-1) receptor agonists has been shown to normalize ER stress response in several in vitro and in vivo models. Early chronic intervention with the GLP-1 receptor agonist liraglutide starting before the onset of metabolic symptoms prevented the development of glucose intolerance, improved insulin and glucagon secretion control, reduced ER stress and inflammation in Langerhans islets in Wfs1 mutant rats. Thus, treatment with GLP-1 receptor agonists might be a promising strategy as a preventive treatment for human WS patients.

Lower Urinary Tract Dysfunction and Associated Pons Volume in Patients with Wolfram Syndrome.

PURPOSE: Wolfram syndrome is a neurodegenerative disorder characterized by childhood onset diabetes mellitus, optic nerve atrophy, diabetes insipidus, hearing impairment, and commonly bladder and bowel dysfunction. We hypothesized that there is an association between a smaller pons, which contains the pontine micturition center, and abnormal lower urinary tract function. MATERIALS AND METHODS: Patients with genetically confirmed Wolfram syndrome attended an annual multidisciplinary research clinic. Subjects underwent noninvasive urodynamic testing and brain magnetic resonance imaging, and completed validated patient reported outcome measures. Bowel and bladder diaries were completed before visits. Age and gender corrected linear and logistic mixed effects models were used to correlate pons volume, corrected for whole brain size, to urodynamic and patient reported outcomes. RESULTS: A total of 36 patients attended 142 visits between 2010 and 2016. Mean age was 16.9 years (range 7 to 30) and 64% of patients were female. Functional bladder capacity was decreased in 31% of the patients, normal in 54% and increased in 14%. Of the patients 44% and 54% had abnormal uroflowmetry and post-void residual, respectively, on at least 1 occasion. There was no increase through time in incidence of lower urinary tract dysfunction. Decreased pons volume was associated with increased post-void residual (p = 0.048) and higher PinQ (Pediatric Incontinence Questionnaire) score (p = 0.011), indicating lower quality of life and higher levels of dysfunction. CONCLUSIONS: A significant number of children, adolescents and young adults with Wolfram syndrome have objective evidence of lower urinary tract dysfunction. Decreased pons volume is associated with more abnormal urinary function and lower quality of life in patients with Wolfram syndrome.

Natural history and clinical characteristics of 50 patients with Wolfram syndrome.

PURPOSE: To describe clinical characteristics of diabetes mellitus (DM) in a group of patients with Wolfram Syndrome (WS). METHODS: Descriptive, cross-sectional observational design. The sample consisted of 50 patients diagnosed with WS. Clinical criteria contributing to WS diagnosis were analyzed: diabetes mellitus (DM), optic nerve atrophy (OA), sensorineural deafness, urological and neurological dysfunction, among others. These parameters were assessed according to their presence/absence, age of onset, and various clinical-analytical parameters. RESULTS: All the patients studied presented DM and OA, with a mean age of onset of 5.4 ± .9 (1-14) years and 9 ± .9 (1-16) years, respectively. The remaining criteria were present with a variable frequency: 77% had diabetes insipidus, 66.7% auditory alterations, 77.8% neurogenic bladder, 61.1% neurological involvement, and 27.8% hypogonadism. A 16.7% of the patients had positive albuminuria (urinary albumin/creatinine ratio > 30 mg/g) and 72.2% had hyporreflexia. There were no significant differences in the age of diagnosis nor of the presence of different pathologies according to sex. CONCLUSIONS: The early presence of a non-autoimmune insulin dependent DM, should alert us of an "infrequent" diabetes syndrome. Wolfram's presumptive diagnosis could be established if juvenile-onset DM occurs concomitantly with OA, and this visual impairment is not attributable to diabetic retinopathy. Despite the long period of evolution of DM and altered values of HbA1c, the prevalence of microvascular complications in the sample are low.

Bladder dysfunction in Wolfram syndrome is highly prevalent and progresses to megacystis.

AIM: Wolfram syndrome is a rare genetic defect in WFS1 or WSF2(CISD2). It includes diabetes mellitus and insipidis, sensorineural deafness, optic atrophy, but not bladder dysfunction. However, this has appeared a common finding in our national referral clinic, and we sought to quantify this problem. METHODS: Data were collected from a multidisciplinary team managing all Wolfram patients in the UK. The following was analyzed: age, date of non-invasive urodynamics (NIU), symptoms, bladder capacity, voided volume, post-void residual and uroflow pattern. Bladder capacity was given as percentage predicted bladder capacity (PBC). Bladders were divided into normal, overactive (OAB), and underactive (UAB). Symptoms, bladder behavior, and genotyping were correlated. Data were expressed as median (interquartile range). MAIN RESULTS: Forty patients with Wolfram syndrome were identified, and 38 underwent NIU. This showed normal bladder function (n=4), OAB (n=9), UAB (n=25). Symptoms were present in only 11 children. The different patterns of bladder behavior (OAB vs. normal vs. UAB) were significantly associated with different %PBC (36 (29-59)% vs. 105 (93-233)% vs. 100 (77.5-337)%; p<0.001), and percentage emptying (100 (80-100)% vs. 100 (87-100)% vs. 69 (48-93)%; p<0.05). There was no association of genotype, symptoms and bladder behavior. Patients with megacystis were older: [13.4 (9.7-16.1) vs. 15.4 (13.9-18.7) years; p<0.05). CONCLUSION: Bladder dysfunction is very common in Wolfram syndrome (~90%), but most children cope (symptoms ~30%). With time there is a significant progression to megacystis, which may represent an underlying neuropathic myogenic failure and is likely to require intervention in the future. LEVEL OF EVIDENCE: Level II (National cohort study of prognosis).