Clinical picture, evolution and peculiar molecular findings in a very large pedigree with Wolfram syndrome

Early presentation of urological abnormalities in a case of Wolfram syndrome

Wolfram syndrome (WS) is a rare autosomal recessive neurodegenerative disorder characterised by arginine vasopressin deficiency (AVP-D), juvenile type 1 diabetes mellitus (DM), optic atrophy (OA) and deafness. We describe an early adolescent female child being managed initially as a case of juvenile type 1 DM presented with urinary retention and diminished visual acuity. Further evaluation confirmed OA and stage IV chronic kidney disease secondary to bilateral hydro-uretero-nephrosis and urinary bladder atrophy. Though AVP-D and sensorineural deafness were absent, the diagnosis of WS was established clinically and confirmed by genetic analysis. Rarity of our case was in the early involvement of bilateral renal tracts. Renal tract involvement in juvenile type 1 DM should raise suspicion of pathology other than microvascular complication. High suspicion and careful evaluation are required to make a diagnosis of WS in juvenile type 1 DM.

Wolfram Syndrome Type I Case Report and Review-Focus on Early Diagnosis and Genetic Variants

Background and Objectives: Wolfram syndrome type 1 (OMIM# 222300; ORPHAcode 3463) is an extremely rare autosomal recessive syndrome with a 25% recurrence risk in children. It is characterized by the presence of juvenile-onset diabetes mellitus (DM), progressive optic atrophy (OA), diabetes insipidus (DI), and sensorineural deafness (D), often referred to by the acronym DIDMOAD. It is a severe neurodegenerative disease with a life expectancy of 39 years, with death occurring due to cerebral atrophy. For a positive diagnosis, the presence of diabetes mellitus and optic nerve atrophy is sufficient. The disease occurs because of pathogenic variants in the WFS1 gene. The aim of this article is to present a case report of Wolfram Syndrome Type I, alongside a review of genetic variants, clinical manifestations, diagnosis, therapy, and long-term management. Emphasizing the importance of early diagnosis and a multidisciplinary approach, the study aims to enhance understanding and improve outcomes for patients with this complex syndrome. Materials and Methods: A case of a 28-year-old patient diagnosed with DM at the age of 6 and with progressive optic atrophy at 26 years old is presented. Molecular diagnosis revealed the presence of a heterozygous nonsense variant WFS1 c.1943G>A (p.Trp648*), and a heterozygous missense variant WFS1 c.1675G>C (p.Ala559Pro). Results: The molecular diagnosis of the patient confirmed the presence of a heterozygous nonsense variant and a heterozygous missense variant in the WFS1 gene, correlating with the clinical presentation of Wolfram syndrome type 1. Both allelic variants found in our patient have been previously described in other patients, whilst this combination has not been described before. Conclusions: This case report and review underscores the critical role of early recognition and diagnosis in Wolfram syndrome, facilitated by genetic testing. By identifying pathogenic variants in the WFS1 gene, genetic testing not only confirms diagnosis but also guides clinical management and informs genetic counseling for affected families. Timely intervention based on genetic insights can potentially reduce the progressive multisystem manifestations of the syndrome, thereby improving the quality of life and outcomes for patients.

Wolfram Syndrome 1: A Pediatrician's and Pediatric Endocrinologist's Perspective

Wolfram syndrome 1 (WS1) is a rare autosomal recessive neurodegenerative disease caused by mutations in WFS1 and WFS2 genes that produce wolframin, a protein involved in endoplasmic reticulum calcium homeostasis and cellular apoptosis. Its main clinical features are diabetes insipidus (DI), early-onset non-autoimmune insulin-dependent diabetes mellitus (DM), gradual loss of vision due to optic atrophy (OA) and deafness (D), hence the acronym DIDMOAD. Several other features from different systems have been reported such as urinary tract, neurological, and psychiatric abnormalities. In addition, endocrine disorders that can appear during childhood and adolescence include primary gonadal atrophy and hypergonadotropic hypogonadism in males and menstrual cycle abnormalities in females. Further, anterior pituitary dysfunction with deficient GH and/or ACTH production have been described. Despite the lack of specific treatment for the disease and its poor life expectancy, early diagnosis and supportive care is important for timely identifying and adequately managing its progressive symptoms. The current narrative review focuses on the pathophysiology and the clinical features of the disease, with a special emphasis on its endocrine abnormalities that appear during childhood and adolescence. Further, therapeutic interventions that have been proven to be effective in the management of WS1 endocrine complications are discussed.

Wolfram Syndrome Type 2: A Systematic Review of a Not Easily Identifiable Clinical Spectrum

Background: Wolfram syndrome (WS) is a rare autosomal recessive disorder that is characterized by the presence of diabetes mellitus, optic atrophy and hearing loss, all of which are crucial elements for the diagnosis. WS is variably associated with diabetes insipidus, neurological disorders, urinary tract anomalies, endocrine dysfunctions and many other systemic manifestations. Since Wolfram and Wagener first described WS in 1938, new phenotypic/genotypic variants of the syndrome have been observed and the clinical picture has been significantly enriched. To date, two main subtypes of WS that associated with two different mutations are known: WS type 1 (WS1), caused by the mutation of the wolframine gene (WS1; 606201), and WS type 2 (WS2), caused by the mutation of the CISD2 gene (WS2; 604928). Methods: A systematic review of the literature was describe the phenotypic characteristics of WS2 in order to highlight the key elements that differentiate it from the classic form. Conclusion: WS2 is the rarest and most recently identified subtype of WS; its clinical picture is partially overlapping with that of WS1, from which it traditionally differs by the absence of diabetes insipidus and the presence of greater bleeding tendency and peptic ulcers.

Urinary Tract Involvement in Wolfram Syndrome: A Narrative Review

Wolfram Syndrome (WS) is a rare neurodegenerative disease with autosomal recessive inheritance and characterized by juvenile onset, non-autoimmune diabetes mellitus and later followed by optic atrophy leading to blindness, diabetes insipidus, hearing loss, and other neurological and endocrine dysfunctions. A wide spectrum of neurodegenerative abnormalities affecting the central nervous system has been described. Among these complications, neurogenic bladder and urodynamic abnormalities also deserve attention. Urinary tract dysfunctions (UTD) up to end stage renal disease are a life-threatening complication of WS patients. Notably, end stage renal disease is reported as one of the most common causes of death among WS patients. UTD have been also reported in affected adolescents. Involvement of the urinary tract occurs in about 90% of affected patients, at a median age of 20 years and with peaks at 13, 21 and 33 years. The aim of our narrative review was to provide an overview of the most important papers regarding urological impairment in Wolfram Syndrome. A comprehensive search on PubMed including Wolfram Syndrome and one or more of the following terms: chronic renal failure, bladder dysfunction, urological aspects, and urinary tract dysfunction, was done. The exclusion criteria were studies not written in English and not including urinary tract dysfunction deep evaluation and description. Studies mentioning general urologic abnormalities without deep description and/or follow-up were not considered. Due to the rarity of the condition, we considered not only papers including pediatric patients, but also papers with pediatric and adult case reports

Longitudinal hearing loss in Wolfram syndrome

BACKGROUND

Wolfram syndrome (WFS) is a rare autosomal recessive disease with clinical manifestations of diabetes mellitus (DM), diabetes insipidus (DI), optic nerve atrophy (OA) and sensorineural hearing loss (SNHL). Although SNHL is a key symptom of WFS, there is limited information on its natural history using standardized measures. Such information is important for clinical care and determining its use as an outcome measure in clinical trials.

METHODS

Standardized audiologic measures, including pure-tone testing, tympanometry, speech perception, and the unaided Speech Intelligibility Index (SII) were assessed in patients with confirmed WFS annually. Mixed model analyses were used to examine main effects of age, time or interactions for pure tone average (PTA), high frequency average (HFA) and SII.

RESULTS

Forty WFS patients were evaluated between 1 and 6 times. Mean age at initial enrollment was 13.5 years (SD = 5.6). Patients were classified as having normal hearing (n = 10), mild-to-severe (n = 24) or profound SNHL (n = 6). Mean age of diagnosis for SNHL was 8.3 years (SD = 5.1) with 75% prevalence. HFA worsened over time for both ears, and SII worsened over time in the worse ear, with greater decline in both measures in younger patients. Average estimated change over 1 year for all measures was in the subclinical range and power analyses suggest that 100 patients would be needed per group (treatment vs. placebo) to detect a 60% reduction in annual change of HFA over 3 years. If trials focused on just those patients with SNHL, power estimates suggest 55 patients per group would be sufficient.

CONCLUSIONS

Most patients had a slow progressive SNHL emerging in late childhood. Change over time with standard audiologic tests (HFA, SII) was small and would not be detectable for at least 2 years in an individual. Relatively large sample sizes would be necessary to detect significant impact on hearing progression in a clinical trial. Hearing function should be monitored clinically in WFS to provide appropriate intervention. Because SNHL can occur very early in WFS, audiologists and otolaryngologists should be aware of and refer for later emerging symptoms.

Audiologic and vestibular findings in Wolfram syndrome

OBJECTIVES

Assessment of auditory and vestibular function in Wolfram Syndrome (WS) patients, using a standardized protocol.

DESIGN

Prospective cohort study of 11 patients using otoscopic inspection, tympanometry, otoacoustic emissions, pure tones, speech in noise (SIN), the Speech Intelligibility Index, and rotational chair testing.

RESULTS

Mean SNHL diagnosis was 7.3 years with 55% prevalence. Four patients with a Speech Intelligibility Index less than 0.75 (better ear) routinely used bilateral amplification devices. Two patients with normal-hearing sensitivity exhibited abnormal SIN scores. The only patient with significant vestibular dysfunction also had a distinctive low-frequency component to her SNHL.

CONCLUSIONS

Hearing loss may occur earlier than previously suspected, and comprehensive testing including SIN testing may reveal deficits not apparent with pure-tone testing. Particular configurations of hearing loss may indicate a need for comprehensive vestibular assessment. Because SNHL can be the first symptom of WS, audiologists and otolaryngologists should be vigilant about referring patients with hearing loss for ophthalmologic examination.

Phenotypical and genotypical expression of Wolfram syndrome in 12 patients from a Sicilian district where this syndrome might not be so infrequent as generally expected

BACKGROUND

Since the original description, there have been only few epidemiological studies of Wolfram syndrome (WS).

AIM

Aims of the present paper are to ascertain WS prevalence and expression in a district of North-eastern Sicily, i.e. a geographic area where consanguineous unions are not very unusual.

MATERIALS AND METHODS

Prevalence rates of WS in the Messina district were calculated by taking into consideration both the total population (653,737) and the populations included within the 0-30 year age range (202,681). We estimated the relative prevalence of WS among patients with youth-onset insulin-dependent diabetes mellitus (DM) who are currently aged under 30 years (256).

RESULTS

Global WS prevalence in our district is 1:54,478, whereas prevalence among individuals under 30 is 1:16,890 and relative prevalence among patients with juvenile-onset insulin-dependent DM is 1:22.3. When compared with the patients with insulin-dependent DM of Messina district, WS patients did not exhibit significant differences in terms of biochemical features at DM onset, whereas age at DM diagnosis was significantly earlier in WS group.

CONCLUSIONS

(a) WS prevalence is not so infrequent as generally expected; (b) in our series, DM presented before 10 years in 11/12 patients and ten cases have already developed all the four peculiar manifestations of WS by 26 years; (c) 9/12 patients exhibited a homozygous frameshift/truncation mutation (Y454_L459del_fsX454), which is the one most frequently found also in patients from other Italian regions; (d) age at DM diagnosis was significantly earlier in WS group than in the patients with insulin-dependent DM of Messina district.

Identification of one novel causative mutation in exon 4 of WFS1 gene in two Italian siblings with classical DIDMOAD syndrome phenotype

The aim of the present paper is to describe a novel missense mutation (G107R) of WFS1 gene that was unexpectedly detected, in two siblings from Southern Italy, outside exon 8; a very unusual finding which has previously been reported only twice in Italian patients with Wolfram syndrome (WS). Although in Spanish pedigrees' WFS1 mutations are frequently located in exon 4, this finding is very infrequent in other pedigrees, particularly in Italian patients.

CONCLUSIONS

a) our report of two siblings with one novel WSF1 mutation (G107R) expands the molecular spectrum of WS; b) this is the 3rd report of Italian patients harbouring one mutation outside exon 8 and the 2nd with one mutation in exon 4; c) on the basis of the present observations, and literature data we can infer that mutation locations outside exon 8 do not seem to be clearly associated with peculiar phenotype expressions of WFS1 gene.

Balance impairment in individuals with Wolfram syndrome

AIM

Wolfram syndrome (WFS), a rare neurodegenerative disorder, is characterized by early onset insulin-dependent diabetes mellitus, optic atrophy, deafness, diabetes insipidus, and neurological abnormalities. Although previously unreported, we hypothesized that neurological complications may be detectable in relatively early stages of the disease. As the cerebellum and brainstem seem particularly vulnerable in WFS, we focused on balance functions critically dependent on these regions. The primary goal of this investigation was to compare balance in young individuals with WFS, in relatively early stages of the disease, to an age-matched cohort using a clinically applicable test.

METHOD

Balance was assessed via the mini-BESTest in 13 children, adolescents and young adults with WFS and 30 typically developing age-matched individuals.

RESULTS

A significant difference was observed between groups in balance as well as in three of four subcomponents of the mini-BESTest and in two timed tasks related to balance. Mini-BESTest scores were correlated with age among typically developing individuals. In the WFS group, mini-BESTest scores were related to overall motor dysfunction, but not age.

INTERPRETATION

Impairments in balance in WFS may occur earlier in the disease process than previously recognized and appear to be related to overall neurological progression rather than chronological age. Recognizing balance impairments and understanding which balance systems contribute to balance deficits in those with WFS may allow for development of effective patient-centered treatment paradigms.

WS1 gene mutation analysis of Wolfram syndrome in a Chinese patient and a systematic review of literatures

Wolfram syndrome is a rare hereditary disease characterized by diabetes mellitus and optic atrophy. The outcome of this disease is always poor. WFS1 gene mutation is the main cause of this disease. A patient with diabetes mellitus, diabetes insipidus, renal tract disorder, psychiatric abnormality, and cataract was diagnosed with Wolfram syndrome. Mutations in open reading frame (ORF) of WFS1 gene was analyzed by sequencing. Mutations in WFS1 gene was also summarized by a systematic review in Pubmed and Chinese biological and medical database. Sequencing of WFS1 gene in this patient showed a new mutation, 1962G>A, and two other non-sense mutations, 2433A>G and 2565G>A. Systematic review included 219 patients in total and identified 172 WFS1 gene mutations, most of which were located in Exon 8. These mutations in WFS1 gene might be useful in prenatal diagnosis of Wolfram syndrome.

Hearing impairment in genotyped Wolfram syndrome patients

OBJECTIVES

Wolfram syndrome is a progressive neurodegenerative syndrome characterized by the features "DIDMOAD" (diabetes insipidus, diabetes mellitus, optic atrophy, and deafness). We sought to study the audiometric data of genotyped Wolfram syndrome patients with sensorineural hearing impairment.

METHODS

Pure tone threshold data of 23 Wolfram syndrome patients were used for cross-sectional analysis in subgroups (age less than 16 years or between 19 and 25 years, gender, and origin).

RESULTS

All subgroups, with 1 exception, showed a fairly similar type of hearing impairment with, on average, thresholds of about 25 dB (range, 0 to 65 dB) at 0.25 to 1 kHz, gently sloping downward to about 60 dB (range, 25 to 95 dB) at 8 kHz. The subgroup of Dutch women, which was excluded from the calculations of the average hearing thresholds, showed a higher degree of hearing impairment. Only the latter subgroup showed progression; however, contrary to the previous longitudinal analysis, progression was not significant in the present cross-sectional analysis, presumably because of the high degree of cross-subject variability.

CONCLUSIONS

This unique collection of audiometric data from genotyped Wolfram syndrome patients shows no substantial progression in sensorineural hearing impairment with advancing age, no relation to the types of WFS1 mutations identified, and, with exclusion of the subgroup of Dutch female patients, no significant sex-related differences.