Wolfram (DIDMOAD) syndrome

Wolfram (DIDMOAD) syndrome: report of two patients

We report a girl with Wolfram syndrome who presented with juvenile-onset diabetes mellitus when she was 4 3/12 years old. Optic atrophy and high frequency sensorineural hearing loss were found at 7 and 9 5/12 years of age, respectively. Her younger brother also developed Wolfram syndrome when he was 3 2/12 years old. Wolfram syndrome is also called DIDMOAD (diabetes insipidus, diabetes mellitus, optic atrophy and deafness). This syndrome is transmitted as an autosomal recessive trait and is a progressive neurodegenerative disorder. It should be considered in a diabetic patient with unexplained optic atrophy, hearing loss, or polyuria and polydipsia in the presence of adequate blood glucose control. Visual acuity should be checked annually in patients with juvenile-onset diabetes mellitus. Optic atrophy should be considered if visual acuity is impaired.

Study of the WFS1 gene and mitochondrial DNA in Spanish Wolfram syndrome families

Wolfram syndrome (WS) is an autosomal recessive neurodegenerative disorder characterized by early onset diabetes mellitus and progressive optic atrophy. Patients with WS frequently develop deafness, diabetes insipidus, renal tract abnormalities, and diverse psychiatric illnesses, among others. A gene responsible for WS was identified on 4p16.1 (WFS1). It encodes a putative 890 amino acid transmembrane protein present in a wide spectrum of tissues. A new locus for WS has been located on 4q22-24, providing evidence for the genetic heterogeneity of this syndrome. Six Spanish families with a total of seven WS patients were screened for mutations in the WFS1-coding region by direct sequencing. We found three previously undescribed mutations c.873C > A, c.1949_50delAT, and c.2206G > C, as well as the duplication c.409_424dup16, formerly published as 425ins16. Several groups had detected deletions in the mitochondrial DNA (mtDNA) of WS patients. For this reason, we also studied the presence of mtDNA rearrangements as well as Leber's hereditary optic neuropathy, mitochondrial encephalomyopathy, lactic acidosis, and stroke-like episodes, and A1555G point mutations in the WS families. No mtDNA abnormalities were detected.

Wolfram syndrome

The Wolfram syndrome is a rare dysmorphogenetic disease of autosomic recessive hereditary nature. The pathogenesis of the disease is still not well known. It is characterised by the presence of diabetes insipidus, diabetes mellitus, optic atrophy and deafness. Other anomalies, such as renal outflow tracts and multiple neurological disorders may develop later. In our case report the diabetes mellitus appeared at the age of 4; the hearing loss and renal disturbances at the age of 11; the optic atrophy at the age of 16. No signs of ataxia, diabetes insipidus and neurologic anomalies were found. The diagnosis of Wolfram syndrome is not always easy in the first stages of the disease. The suspect may come from the presence of a juvenile diabetes mellitus asssociated with optic atrophy. For the diagnosis a valid clue can be given from the results of some clinical tests such as the positivity of the visual evoked potentials and the retinogram reliefs and the exclusion of the autoimmune origin of the diabetes mellitus. Other signs such as the progressive sensorineural hearing loss, the presence of nystagmus and of urodynamic disturbances and renal complications makes the diagnosis of this syndrome easier.

Wolfram (DIDMOAD) syndrome: a multidisciplinary clinical study in nine Turkish patients and review of the literature

AIM

To study Wolfram syndrome (WFS) with multidisciplinary consultations and compare the results with the literature.

METHODS

Nine patients fulfilled the ascertainment criteria of WFS (insulin-dependent diabetes mellitus and optic atrophy). All patients were evaluated by the departments of paediatrics, ophthalmology, audiology, urology and medical biology.

RESULTS

The earliest manifestation of WFS was insulin-dependent diabetes mellitus (at a median age of 6.9 y), followed by optic atrophy (8.9 y), diabetes insipidus (10.2 y) and deafness (10.5 y). Short stature was found in five cases, delayed puberty in two cases and hypergonadotropic hypogonadism in one case. Audiography disclosed hearing loss at high frequency in all patients (100%), but only five patients had clinical subjective hearing problems. Intravenous pyelography revealed hydroureteronephrosis in eight patients. Urodynamics revealed a normal bladder in only one patient. Three patients had a low-capacity, low-compliance bladder, detrusor external sphincteric dyssynergia and emptying problem, while five had an atonic bladder. Ocular findings were optic atrophy, low visual acuity and colour vision defects. Visual field tests revealed concentric and/or peripheral diminution in five patients. Visual evoked potentials were abnormal (reduced amplitude to both flash and pattern stimulation) in seven patients. Cranial magnetic resonance imaging showed mild or moderate atrophy of the optic nerves, chiasm, cerebellum, basal ganglia and brainstem in six patients; there was a partially empty sella in one case. There was no evidence of mitochondrial tRNA(Leu) (UUR) A to G (nucleotide 3243) mutation.

CONCLUSION

Wolfram syndrome should be evaluated in a multidisciplinary manner. Some specific and dynamic tests are necessary to make a more precise estimate of the prevalence and median age of the components of WFS. Short stature is a common feature in WFS. Hypogonadism may be hypogonadotropic or hypergonadotropic. Bladder dysfunction does not always present as a large atonic bladder in WFS. A low-capacity, high-pressure bladder with sphincteric dyssynergia is also common.

Molecular detection of novel WFS1 mutations in patients with Wolfram syndrome by a DHPLC-based assay

Wolfram syndrome (WS) is a recessively inherited mendelian form of diabetes and neurodegeneration also known by the acronym DIDMOAD from the major clinical features, including diabetes insipidus, diabetes mellitus, optic atrophy, and deafness. Affected individuals may also show renal tract abnormalities as well as multiple neurological and psychiatric symptoms. The causative gene for WS (WFS1) encoding wolframin maps to chromosome 4p16.1 and consists of eight exons, spanning 33.44 Kb of genomic DNA. In this study we report on the mutational analysis of the WFS1 coding region in 19 Italian WS patients and 25 relatives, using a DHPLC-based protocol. A total of 19 different mutations in WFS1 were found in 18 of 19 patients (95%). All these mutations, except one, are novel, preferentially located in WFS1 exon 8, and include deletions, insertions, duplications, and nonsense and missense changes. In particular, a 16 base-pair deletion in WFS1 codon 454 was detected in five different unrelated nuclear families, being the most prevalent alteration in this Italian group. Nine neutral changes and polymorphisms were also identified. Overall, this study represents the molecular characterization of the largest cohort of Italian WS patients and carriers studied so far, and increases the number of identified WFS1 allelic variants worldwide.

Genetic epidemiology of type 1 diabetes

Family and twin studies indicate that a substantial fraction of susceptibility to type 1 diabetes is attributable to genetic factors. These and other epidemiologic studies also implicate environmental factors as important triggers. Although the specific environmental factors that contribute to immune-mediated diabetes remain unknown, several of the relevant genetic factors have been identified using two main approaches: genome-wide linkage analysis and candidate gene association studies. This article reviews the epidemiology of type 1 diabetes, the relative merits of linkage and association studies, and the results achieved so far using these two approaches. Prospects for the future of type 1 diabetes genetics research are considered.

A case showing an association between type 1 diabetes mellitus and Kabuki syndrome

The case of a 31-year-old female suffering from type 1 diabetes mellitus (DM) and Kabuki syndrome is presented. The patient was diagnosed as having impaired glucose tolerance (IGT) at age 18; secondary amenorrhea occurred at age 20, following acute body weight loss. Extensive examination revealed the patient to have a slowly progressive form of type 1 DM and, based on the physical findings, including her facial features, she was diagnosed as also having congenital Kabuki syndrome. Since then, this patient has experienced several episodes of diabetic ketoacidosis, all of which were brought about by prolonged bronchial infection. Although it is perhaps reasonable at present to consider this case to represent a chance association, further clinical investigations will be carried out to clarify whether or not Kabuki syndrome and type 1 DM have any common pathogenic features.

WFS1 mutations in Spanish patients with diabetes mellitus and deafness

Wolfram syndrome (WS) is an autosomal recessive neurodegenerative disorder characterised by early onset diabetes mellitus and progressive optic atrophy, as well as other clinical features such as deafness, diabetes insipida, renal tract abnormalities and diverse psychiatric illnesses. A gene responsible for WS was identified in 4p16.1 (WFS1). It encodes a putative 890 amino acid transmembrane protein expressed in a wide spectrum of tissues. Recently, a new locus for WS has been located on 4q22-24, providing additional evidence for the genetic heterogeneity of this syndrome. We have studied the presence of WFS1 variants in three groups of individuals: patients with diabetes mellitus, patients with deafness and patients with both conditions. A fourth group of healthy subjects was used as control. We have identified a total of 18 nucleotide changes in the WFS1 gene: three mutations and 15 polymorphisms. Six of these changes were previously undescribed. Four of the 15 polymorphisms studied among the patients group present statistical differences in the allelic and genotypic distribution when comparing affected vs control groups.

Wolfram syndrome: identification of a phenotypic and genotypic variant from Jordan

Wolfram syndrome is an autosomal recessive disorder with probable locus heterogeneity. Only insulin-dependent diabetes mellitus and progressive optic-nerve atrophy are necessary to make the diagnosis, but associated findings include diabetes insipidus, sensorineural hearing loss, ataxia, peripheral neuropathy, urinary-tract atony, and psychiatric illnesses. We performed clinical and molecular studies on four consanguineous families with 16 affected individuals. We point out a new phenotypic variant with absent diabetes insipidus, presence of peptic ulcer disease and bleeding tendency secondary to a platelet aggregation defect. The same phenotypic variant turned out to be a genotypic variant with linkage to a second Wolfram syndrome locus (WFS2) on chromosome 4q22-24.

Exploring the perceived world of the deaf-blind: on the development of an instrument

In the present interview study on a sample of 13 deaf-blind participants (eight Usher patients and five with other diagnoses), all but one with some remaining visual function and all but two with a pure-tone average (PTA) exceeding 100 dB HL, an instrument was developed to assess discovery and localization abilities (DILO), compensatory use of sensory information, emotional and cognitive aspects of communication, and the preferred use of technical aids. Both qualitative and quantitative data were collected, and it was found that (1) the importance of early discovery of events and persons is rated high, (2) vision ranks higher than other sensory information, and airflow, smell and residual hearing come next in the perceptual world of this sample, (3) cognitive aspects of communication correlate with the importance of discovery and localization, and (4) technical aids dominated by vision and vibratory senses are preferred. It is concluded that even a small remaining visual function could be of significant importance in rehabilitation. Finally, in the deaf-blind group of subjects with some remaining visual function, utilization of remaining vision was felt to be more important than utilization of other sensory modalities.

Ophthalmologic findings in fifteen patients with Wolfram syndrome

PURPOSE

To look for ophthalmologic abnormalities in 15 patients with Wolfram syndrome, also known as DIDMOAD syndrome (diabetes insipidus, diabetes mellitus, optic atrophy and deafness).

METHODS

Fifteen patients from four inbred families diagnosed as having Wolfram syndrome at the National Center for Diabetes, Endocrinology and Genetics, in Amman, Jordan, were evaluated ophthalmologically. Their examination included best-corrected visual acuity, color vision testing, pupillary light reflexes, slit-lamp biomicroscopy and fundus examination. Fundus fluorescein angiography was done in all patients.

RESULTS

The prevalence of optic atrophy was (93.3%), colordefect (92.9%), cataract (66.6%), pigmentary retinopathy (30%) and diabetic retinopathy (20%). Abnormal pupillary light reflexes and nystagmus were also reported.

CONCLUSIONS

Although ourgroup of patients was genetically heterogeneous, the ophthalmic findings are consistent with those reported in other series, except for cataract which was highly prevalent but mild and did not contribute significantly to loss of vision.

A review and evaluation of research on the deaf-blind from perceptual, communicative, social and rehabilitative perspectives

This paper reviews research on deaf-blind individuals, primarily from behavioral and communicative points of view. Inclusion in the population of deaf-blind is qualified by describing a variety of subgroups and genetically based syndromes associated with deaf-blindness. Sensory assessment procedures--based primarily on residual capacities--are appraised. Consequences for everyday life are described briefly. Non-sensory, alternative classificatory schemes and procedures are presented and the results from behavior modification procedures used for correcting maladaptive behaviors are summarized. Methods for communicating tactilely are described and evaluated. Attention is also drawn to some suggestions regarding learning of alphabetic codes and sign acquisition. Finally, suggestions for future research are proposed.

Presence of a major WFS1 mutation in Spanish Wolfram syndrome pedigrees

Wolfram syndrome (WS) is an autosomal recessive neurodegenerative disease mainly characterized by familial diabetes mellitus and optic atrophy. WS patients frequently present with other clinical features such as diabetes insipidus, renal abnormalities, psychiatric disorders, and a variety of neurologic symptoms: deafness, ataxia, peripheral neuropathy. A gene responsible for Wolfram Syndrome (WFS1) has been recently identified on chromosome 4p16.1. Twenty-two Wolfram patients from 16 Spanish families were screened for mutations in the WFS1 coding region by SSCP analysis and direct sequencing. Since WS has been considered a mitochondrial disorder for some time, mitochondrial DNA (mtDNA) in these families was also examined. WFS1 mutations were detected in 75% of families (12 of 16). One of these mutations, an insertion of 16 base pairs in exon 4, turned out to be notably frequent in Spanish pedigrees. As many as 50% of pedigrees with WFS1 mutations harbored this insertion, either in one (33% of cases) or in two chromosomes (67%). Ten other mutations were identified: 7 missense changes, 2 deletions, and 1 nonsense mutation. Only 3 of these changes had been previously described in non-Spanish pedigrees. Large mtDNA rearrangements and LHON point mutations were detected in four and six families, respectively. No correlation could be established between WFS1 gene mutations and specific point mutations or rearrangements in mtDNA. We would suggest first screening for the 16-bp insertion in exon 4 when a new Spanish WS case is reported.

Homozygosity mapping identifies an additional locus for Wolfram syndrome on chromosome 4q

Wolfram syndrome, which is sometimes referred to as "DIDMOAD" (diabetes insipidus, diabetes mellitus, optic atrophy, and deafness), is an autosomal recessive neurodegenerative disorder for which only insulin-dependent diabetes mellitus and optic atrophy are necessary to make the diagnosis. Researchers have mapped Wolfram syndrome to chromosome 4p16.1, and, recently, a gene encoding a putative transmembrane protein has been cloned and mutations have been identified in patients. To pursue the possibility of locus heterogeneity, 16 patients from four different families were recruited. These patients, who have the Wolfram syndrome phenotype, also have additional features that have not previously been reported. There is an absence of diabetes insipidus in all affected family members. In addition, several patients have profound upper gastrointestinal ulceration and bleeding. With the use of three microsatellite markers (D4S432, D4S3023, and D4S2366) reported to be linked to the chromosome 4p16.1 locus, we significantly excluded linkage in three of the four families. The two affected individuals in one family showed homozygosity for all three markers from the region of linkage on chromosome 4p16.1. For the other three families, genetic heterogeneity for Wolfram syndrome was verified by demonstration of linkage to chromosome 4q22-24. In conclusion, we report the unique clinical findings and linkage-analysis results of 16 patients with Wolfram syndrome and provide further evidence for the genetic heterogeneity of this disorder. We also provide data on a new locus that plays a role in the etiology of insulin-dependent diabetes mellitus.

Missense variations of the gene responsible for Wolfram syndrome (WFS1/wolframin) in Japanese: possible contribution of the Arg456His mutation to type 1 diabetes as a nonautoimmune genetic basis

Recently, a novel gene for a putative transmembrane protein (WFS1/wolframin) was found to be mutated in patients with Wolfram syndrome or DI-DM-OA-D (diabetes insipidus, diabetes mellitus, optic atrophy, and deafness) syndrome. It is suggested that the WFS1 protein is important in the survival of islet beta-cells. We studied the WFS1 gene in a Japanese population to assess its possible role in common type 1 diabetes. Mutation screening revealed four missense mutations; R456H, G576S, H611R, and I720V. By genetic association studies of 185 type 1 diabetes patients and 380 control subjects, we found that R456H was significantly increased in the type 1 diabetes group compared to the control group (P = 0.0005); H611R and I720V were also significantly increased with weaker significance. Furthermore, in patients with the R456H mutation, type 1 diabetes-resistant HLA-DRB1 alleles (DRB1*0406, 1501, and 1502) were significantly increased compared to mutation-negative patients while susceptible DRB1*0901 was significantly decreased. Frequencies of autoimmunity characteristics (ICA or GAD-Ab positiveness and combination of autoimmune thyroid disease) were decreased in the R456H-positive patients compared to the R456H-negative patients. These data suggest that the WFS1 gene may have a role in the development of common type 1 diabetes as a nonautoimmune genetic basis.

Mitochondrial disorders: clinical and genetic features

Virtually all cells in humans depend on mitochondrial oxidative phosphorylation to generate energy, accounting for the remarkable diversity of clinical disorders associated with mitochondrial DNA mutations. However, certain tissues are particularly susceptible to mitochondrial dysfunction, resulting in recognizable clinical syndromes. Mitochondrial DNA mutations have been linked to seizures, strokes, optic atrophy, neuropathy, myopathy, cardiomyopathy, sensorineural hearing loss, diabetes mellitus, and other clinical features. Mitochondrial DNA mutations also may play an important role in aging, as well as in common age-related neurodegenerative disorders such as Parkinson's disease. Therefore, it is becoming increasingly important for clinicians to recognize the clinical syndromes suggestive of a mitochondrial disorder, and to understand the unique features of mitochondrial genetics that complicate diagnosis and genetic counseling.

A gene encoding a transmembrane protein is mutated in patients with diabetes mellitus and optic atrophy (Wolfram syndrome)

Wolfram syndrome (WFS; OMIM 222300) is an autosomal recessive neurodegenerative disorder defined by young-onset non-immune insulin-dependent diabetes mellitus and progressive optic atrophy. Linkage to markers on chromosome 4p was confirmed in five families. On the basis of meiotic recombinants and disease-associated haplotypes, the WFS gene was localized to a BAC/P1 contig of less than 250 kb. Mutations in a novel gene (WFS1) encoding a putative transmembrane protein were found in all affected individuals in six WFS families, and these mutations were associated with the disease phenotype. WFS1 appears to function in survival of islet beta-cells and neurons.