A novel detrimental homozygous mutation in the WFS1 gene in two sisters from nonconsanguineous parents with untreated diabetes insipidus.
ABSTRACT: Given the limited lifespan and with the recent progress in experimental treatments for WS, timely diagnosis and multidisciplinary treatment for DI/DM, hydronephrosis, and visual/psychiatric status-maintaining quality of life-are of crucial importance.
Project description:Wolfram syndrome (WS) is a rare, degenerative, and hereditary disorder characterized by ear diabetes mellitus (DM) and optic atrophy (OA). We aim to characterize clinical features in Chinese patients who had been poorly studied until now.We performed a retrospective review of patients with WS seen in the Peking Union Medical College Hospital from 2002 to 2017. Data including demographic data, clinical presentations, examination results, family history, and genetic analysis were described.Six patients with WS were identified, meeting the diagnostic criteria of the coincidence of DM and OA before 15?years old or the existence of two WFS1 mutations. All were male, with the median age of 14.5?years (range 10-19 years). Blood glucose impairment, OA, and diabetes insipidus were present in all (100%), hearing impairment in four (66.7%), urological abnormalities in four (66.7%), neurological abnormalities in one (16.7%), and endocrine disorder in one (16.7%). Rare presentation includes cataract, glaucoma, and spina bifida occulta. Diabetes was insulin-dependent and not ketosis onset, with antibody to glutamic acid decarboxylase and islet cell negative. Genetic analysis revealed mutations in WFS1 in three patients. A novel frameshift mutation (p.Asp151Glufs*93) was identified in exon 4 of WFS1.Our series of WS patients indicated that WS is a degenerative disease with a wide and variable spectrum, characterized by ear non-autoimmune DM and bilateral OA. Genetic analysis is recommended when suspected of WS.
Project description:Wolfram syndrome (WS) is an autosomal recessive neurodegenerative disorder characterized by diabetes mellitus (DM), optic atrophy (OA), central diabetes insipidus (CDI) and deafness (D). The phenotype of the disease has been associated with several mutations in the WFS1 gene, a nuclear gene localized on chromosome 4. Since the discovery of the association between WFS1 gene and Wolfram syndrome, more than 150 mutations have been identified in WS patients. We previously described the first case of perinatal onset of Wolfram syndrome newborn carrying a segmental uniparental heterodysomy affecting the short arm of chromosome 4 responsible for a significant reduction in wolframin expression. Here we review and discuss the pathophysiological mechanisms that we believe responsible for the perinatal onset of Wolfram syndrome as these data strongly suggest a role for WFS1 gene in foetal and neonatal neurodevelopment.We described a male patient of 30 weeks' gestation with intrauterine growth restriction and poly-hydramnios. During the first days of life, the patient showed a 19% weight loss associated with polyuria and hypernatremia. The presence of persistent hypernatremia (serum sodium 150 mEq/L), high plasma osmolarity (322 mOsm/L) and low urine osmolarity (190 mOsm/l) with a Uosm/Posm ratio < 1 were consistent with CDI. The diagnosis of CDI was confirmed by the desmopressin test and the brain magnetic resonance imaging (MRI) at 34 weeks of age, that showed the lack of posterior pituitary hyperintense signal. In addition, a bilateral asymmetrical optic nerve hypoplasia associated with right orbital bone hypoplasia was observed, suggesting the diagnosis of WF. During the five years follow-up the patient did not developed glucose intolerance or diabetes mellitus. By the end of the second year of life, primary non-autoimmune central hypothyroidism and mild neurodevelopment retardation were diagnosed.The analysis of our case, in the light of the most recent literature, suggests a possible role for WFS1 gene in the development of certain brain structures during the fetal period. Wolfram syndrome should be considered in the differential diagnosis of the rare cases of congenital central diabetes insipidus developed in the neonatal period.
Project description:Wolfram syndrome (WS) is a rare autosomal recessive neurodegenerative disorder characterized by the presentation of early onset type I diabetes mellitus and optic atrophy with later onset diabetes insipidus and deafness. WFS1 gene was identified on chromosome 4p16.1 as the gene responsible for WS disease given that most of the WS patients were found to carry mutations in this gene. This study was carried out to investigate the molecular spectrum of WFS1 gene in Jordanian families. Molecular and clinical characterization was performed on five WS patients from two unrelated Jordanian families. Our data indicated that WS patients of the first family harbored two deletion mutations (V415del and F247fs) located in exon 8 and exon 7 respectively, with a compound heterozygous pattern of inheritance; while in the second family, we identified a novel nonsense mutation (W185X) located in exon 5 in the N-terminal cytoplasmic domain with a homozygous pattern of inheritance. This mutation can be considered as loss of function mutation since the resulting truncated protein lost both the transmembrane domain and the C-terminal domain. Additionally, the W185X mutation lies within the CaM binding domain in wolframin protein which is thought to have a role in the regulation of wolframin function in response to calcium levels.
Project description:BACKGROUND:Nephrogenic diabetes insipidus (DI) secondary to a urinary tract obstruction is a rare condition. Herein, we report a case of partial nephrogenic DI due to obstructive uropathy in a patient with Castleman's disease. CASE PRESENTATION:A 78-year-old man underwent computed tomography (CT) at his local hospital because of persistent edema of the leg and polyuria (both lasting approximately 2 months); retroperitoneal fibrosis was detected on the CT scan. An abdominal CT scan showed bilateral hydronephrosis, and a surgical biopsy of the para-aortic lymph node revealed Castleman's disease. To resolve the hydronephrosis, a double J stent was inserted; however, his polyuria continued. As his serum osmolality (311 mOsm/kg) was greater than 300 mOsm/kg, and his serum sodium level was 149 mEq/L, a water deprivation test was not performed. On a vasopressin challenge test, his urine was not sufficiently concentrated to the expected range, indicating partial nephrogenic DI. He was treated with hydrochlorothiazide (25 mg/day), and his urine output gradually decreased to within the normal range. The patient recovered uneventfully and underwent treatment for Castleman's disease. CONCLUSION:To the best of our knowledge, this is the first case of partial nephrogenic DI due to obstructive uropathy associated with Castleman's disease.
Project description:Wolfram syndrome (WS) is a rare, progressive, neurodegenerative disorder that has an autosomal recessive pattern of inheritance. The gene for WS, wolfram syndrome 1 gene (WFS1), is located on human chromosome 4p16.1 and encodes a transmembrane protein. To date, approximately 230 mutations in WFS1 have been confirmed, in which nonsynonymous single nucleotide polymorphisms (nsSNPs) are the most common forms of genetic variation. Nonetheless, there is poor knowledge on the relationship between SNP genotype and phenotype in other nsSNPs of the WFS1 gene. Here, we analysed 395 nsSNPs associated with the WFS1 gene using different computational methods and identified 20 nsSNPs to be potentially pathogenic. Furthermore, to identify the amino acid distributions and significances of pathogenic nsSNPs in the protein of WFS1, its transmembrane domain was constructed by the TMHMM server, which suggested that mutations outside of the TMhelix could have more effects on protein function. The predicted pathogenic mutations for the nsSNPs of the WFS1 gene provide an excellent guide for screening pathogenic mutations.
Project description:OBJECTIVE:The Williams-Beuren syndrome (WS) is associated with impaired glucose metabolism (IGM) early in adulthood. However, the pathophysiology of IGM remains poorly defined, due to the lack of longitudinal studies investigating the contribution of ?-cell dysfunction and impaired insulin sensitivity. This study aimed at assessing incidence of IGM and the underlying mechanisms in WS adults. METHODS:This observational, longitudinal (5-year), cohort study enrolled thirty-one consecutive WS subjects attending a tertiary referral center. An oral glucose tolerance test (OGTT) was performed yearly and used to classify patients as normal or IGM, including impaired fasting glucose (IFG) and/or impaired glucose tolerance (IGT) and diabetes mellitus (DM), and to calculate surrogate measures of insulin secretion and/or sensitivity. RESULTS:IGM patients were 18 (58.1%, three DM) at baseline and 19 (61.3%, five DM) at end-of-follow-up. However, 13 individuals changed category of glucose homeostasis in both directions during follow-up (8 progressors, 5 regressors) and 18 did not (8 non-progressors, 10 non-regressors). New cases of IGM and DM were 11.1 and 2.53 per 100 persons-year, respectively, and were treated non-pharmacologically. In the whole cohort and, to a higher extent, in progressors, indices of early-phase insulin secretion and insulin sensitivity decreased significantly from baseline to end-of-follow-up, with concurrent reduction of the oral disposition index and insulin secretion-sensitivity index-2 (ISSI-2), compensating insulin secretion for the level of insulin resistance. No baseline measure independently predicted progression, which correlated with change from baseline in ISSI-2. Compared with patients with normal glucose homeostasis, IGT subjects had impaired insulin sensitivity, whereas insulin secretion was reduced only in those with IFG+IGT or DM. CONCLUSIONS:IGM incidence is high in young adults with WS, suggesting the need of early screening and timed intervention. As in classical type 2 diabetes, impaired insulin sensitivity and ?-cell dysfunction contribute, in this sequence, to progression to IGM and DM.
Project description:Wolfram syndrome (WS) is a rare autosomal-recessive disorder that is caused by mutations in the WFS1 gene and is characterized by juvenile-onset diabetes, optic atrophy, hearing loss and a number of other complications. Here, we describe the creation and phenotype of Wfs1 mutant rats, in which exon 5 of the Wfs1 gene is deleted, resulting in a loss of 27 amino acids from the WFS1 protein sequence. These Wfs1-ex5-KO232 rats show progressive glucose intolerance, which culminates in the development of diabetes mellitus, glycosuria, hyperglycaemia and severe body weight loss by 12 months of age. Beta cell mass is reduced in older mutant rats, which is accompanied by decreased glucose-stimulated insulin secretion from 3 months of age. Medullary volume is decreased in older Wfs1-ex5-KO232 rats, with the largest decreases at the level of the inferior olive. Finally, older Wfs1-ex5-KO232 rats show retinal gliosis and optic nerve atrophy at 15 months of age. Electron microscopy revealed axonal degeneration and disorganization of the myelin in the optic nerves of older Wfs1-ex5-KO232 rats. The phenotype of Wfs1-ex5-KO232 rats indicates that they have the core symptoms of WS. Therefore, we present a novel rat model of WS.
Project description:NF-E2-related factor-2 (Nrf2) regulates cellular responses to oxidative and electrophilic stress. Loss of Keap1 increases Nrf2 protein levels, and Keap1-null mice die of oesophageal hyperkeratosis because of Nrf2 hyperactivation. Here we show that deletion of oesophageal Nrf2 in Keap1-null mice allows survival until adulthood, but the animals develop polyuria with low osmolality and bilateral hydronephrosis. This phenotype is caused by defects in water reabsorption that are the result of reduced aquaporin 2 levels in the kidney. Renal tubular deletion of Keap1 promotes nephrogenic diabetes insipidus features, confirming that Nrf2 activation in developing tubular cells causes a water reabsorption defect. These findings suggest that Nrf2 activity should be tightly controlled during development in order to maintain renal homeostasis. In addition, tissue-specific ablation of Nrf2 in Keap1-null mice might create useful animal models to uncover novel physiological functions of Nrf2.
Project description:West syndrome (WS), defined by the triad of infantile spasms, pathognomonic hypsarrhythmia and developmental regression, is a rare epileptic disease affecting about 1:3500 live births. To get better insights on the genetic of this pathology, we exome-sequenced the members of a consanguineous family affected with isolated WS. We identified a homozygous variant (c.1825G>T/p.(Ala609Ser)) in the GUF1 gene in the three affected siblings. GUF1 encodes a protein essential in conditions that counteract faithful protein synthesis: it is able to remobilize stuck ribosomes and transiently inhibit the elongation process to optimize protein synthesis. The variant identified in the WS family changes an alanine residue conserved in all eukaryotic organisms and positioned within the tRNA-binding moiety of this nuclear genome-encoded mitochondrial translational elongation factor. Yeast complementation assays show that the activity of GUF1(A609S) is modified in suboptimal environments. We suggest a new link between improper assembly of respiratory chain complexes and WS.
Project description:BACKGROUND: Wolfram syndrome (WFS) is a recessive neurologic and endocrinologic degenerative disorder, and is also known as DIDMOAD (Diabetes Insipidus, early-onset Diabetes Mellitus, progressive Optic Atrophy and Deafness) syndrome. Most affected individuals carry recessive mutations in the Wolfram syndrome 1 gene (WFS1). However, the phenotypic pleiomorphism, rarity and molecular complexity of this disease complicate our efforts to understand WFS. To address this limitation, we aimed to describe complications and to elucidate the contributions of WFS1 mutations to clinical manifestations in Japanese patients with WFS. METHODOLOGY: The minimal ascertainment criterion for diagnosing WFS was having both early onset diabetes mellitus and bilateral optic atrophy. Genetic analysis for WFS1 was performed by direct sequencing. PRINCIPAL FINDINGS: Sixty-seven patients were identified nationally for a prevalence of one per 710,000, with 33 patients (49%) having all 4 components of DIDMOAD. In 40 subjects who agreed to participate in this investigation from 30 unrelated families, the earliest manifestation was DM at a median age of 8.7 years, followed by OA at a median age of 15.8 years. However, either OA or DI was the first diagnosed feature in 6 subjects. In 10, features other than DM predated OA. Twenty-seven patients (67.5%) had a broad spectrum of recessive mutations in WFS1. Two patients had mutations in only one allele. Eleven patients (27.5%) had intact WFS1 alleles. Ages at onset of both DM and OA in patients with recessive WFS1 mutations were indistinguishable from those in patients without WFS1 mutations. In the patients with predicted complete loss-of-function mutations, ages at the onsets of both DM and OA were significantly earlier than those in patients with predicted partial-loss-of function mutations. CONCLUSION/SIGNIFICANCE: This study emphasizes the clinical and genetic heterogeneity in patients with WFS. Genotype-phenotype correlations may exist in patients with WFS1 mutations, as demonstrated by the disease onset.