Disease relevance of DFNA40

• Transient conductive hearing impairment was found in 16 per cent of the sample, but in no case was there apparent improvement in a sensorineural deficit over time [1].
• Thiamine-responsive megaloblastic anaemia syndrome (TRMA; MIM 249270) is an autosomal recessive disorder with features that include megaloblastic anaemia, mild thrombocytopenia and leucopenia, sensorineural deafness and diabetes mellitus [2].
• Thus, our results suggest that mutations in MYH9 result in three megakaryocyte/platelet/leukocyte syndromes and are important in the pathogenesis of sensorineural deafness, cataracts and nephritis [3].
• Usher syndrome type 1 (USH1) is an autosomal recessive sensory defect involving congenital profound sensorineural deafness, vestibular dysfunction and blindness (due to progressive retinitis pigmentosa)1 [4].
• Mutation of BSND causes Bartter syndrome with sensorineural deafness and kidney failure [5].

Psychiatry related information on DFNA40

• Only 14 children (14 percent) had persisting neurologic sequelae: sensorineural hearing loss in 11 (unilateral in 6 and bilateral in 5), seizure disorder in 2, and hemiplegia and mental retardation in 1 [6].
• MELAS is a mitochondrial encephalomyopathy characterized clinically by recurrent stroke-like episodes, seizures, sensorineural deafness, dementia, hypertrophic cardiomyopathy, and short stature [7].
• Progressive optic atrophy and sensorineural hearing loss due to chronic glue sniffing [8].
• Mercury is known to cause sensorineural hearing loss and impaired speech perception [9].
• Auditory stimulus intensity and reaction time in listeners with longstanding sensorineural hearing loss [10].

High impact information on DFNA40

• Unlike previously described sensorineural deafness genes, all of which underlie cochlear cell pathologies, DFNB59 is the first human gene implicated in nonsyndromic deafness due to a neuronal defect [11].
• Mutation in the transcriptional coactivator EYA4 causes dilated cardiomyopathy and sensorineural hearing loss [12].
• We find that the affected individuals of two families also presented with progressive sensorineural high-frequency hearing loss (gene DFNA39) [13].
• Additional aspects of the phenotype include sensorineural deafness, reduced lifespan and decreased reproductive fitness [14].
• We have identified two frameshift mutations and a large deletion in the copy containing 29 coding exons in two families affected by autosomal recessive non-syndromal sensorineural deafness linked to the DFNB16 locus [15].

Chemical compound and disease context of DFNA40

• Thiamine-responsive megaloblastic anaemia (TRMA), also known as Rogers syndrome, is an early onset, autosomal recessive disorder defined by the occurrence of megaloblastic anaemia, diabetes mellitus and sensorineural deafness, responding in varying degrees to thiamine treatment (MIM 249270) [16].
• Patients with a nonsense mutation in CD151 display end-stage kidney failure associated with regional skin blistering and sensorineural deafness, and mice lacking the integrin alpha3 subunit die neonatally because of severe abnormalities in the lung and kidney epithelia [17].
• The objective of this study was to determine whether a mitochondrial DNA mutation and defective oxidative phosphorylation are present in a pedigree with maternally inherited sensorineural deafness, levodopa-responsive parkinsonism, and neuropathy [18].
• Pendred's syndrome is an autosomal recessive disorder characterized by sensorineural deafness, goiter, and impaired iodide organification [19].
• The affected subject was a 22-yr-old man with a history of myoclonic epilepsy and mild sensorineural hearing loss, a 1-yr duration of diabetes mellitus, and a low level C peptide response to oral glucose [20].

Biological context of DFNA40

• Using positional information from a patient with a 21-kb deletion in chromosome Xq22 and sensorineural deafness along with dystonia, we characterized a novel transcript lying within the deletion as a candidate for this complex syndrome [21].
• Usher syndrome type IIa (OMIM 276901), an autosomal recessive disorder characterized by moderate to severe sensorineural hearing loss and progressive retinitis pigmentosa, maps to the long arm of human chromosome 1q41 between markers AFM268ZD1 and AFM144XF2 [22].
• DFNB3, a locus for nonsyndromic sensorineural recessive deafness, maps to a 3-centimorgan interval on human chromosome 17p11.2, a region that shows conserved synteny with mouse shaker-2 [23].
• Blood viscosity as a factor in sensorineural hearing impairment [24].
• Ablation or missense mutations of the pump cause deafness, as described for the G283S mutation in the deafwaddler (dfw) mouse [25].

Anatomical context of DFNA40

• Our findings revealed a unique ultrastructural malformation of inner-ear architecture associated with non-syndromic hearing loss, and suggest that tectorial membrane abnormalities may be one aetiology of sensorineural hearing loss primarily affecting the mid-frequencies [26].
• Patients with ATP6B1 mutations also have sensorineural hearing loss; consistent with this finding, we demonstrate expression of ATP6B1 in cochlea and endolymphatic sac [27].
• Pendred syndrome is an autosomal recessive disorder associated with developmental abnormalities of the cochlea, sensorineural hearing loss and diffuse thyroid enlargement (goitre) [28].
• To our knowledge, this is the first non-syndromic sensorineural autosomal deafness susceptibility gene to be identified, which implicates Cx26 as an important component of the human cochlea [29].
• Screening is endorsed by most professional organizations, including the US Preventive Services Task Force. While most hearing loss in older adults is sensorineural and due to presbycusis, cerumen impaction and chronic otitis media may be present in up to 30% of elderly patients with hearing loss and can be treated by the primary care clinician [30].

Associations of DFNA40 with chemical compounds

• As compared with those who received placebo, the patients who received dexamethasone became afebrile earlier (1.6 vs. 5.0 days; P less than 0.001) and were less likely to acquire moderate or more severe bilateral sensorineural hearing loss (15.5 vs. 3.3 percent; P less than 0.01) [31].
• Pharmacological doses of thiamine correct the anaemia, and in some cases improve the diabetes, although progressive sensorineural deafness is irreversible [32].
• Stickler and Marshall syndromes are dominantly inherited chondrodysplasias characterized by midfacial hypoplasia, high myopia, and sensorineural-hearing deficit [33].
• Mutations in the Wolfram syndrome 1 gene (WFS1) are a common cause of low frequency sensorineural hearing loss [34].
• Steroid-responsive postinfectious sensorineural hearing loss [35].

Physical interactions of DFNA40

• Otosclerosis is a disease of complex unknown etiology causing progressive conductive and/or sensorineural hearing loss (HL) [36].

Other interactions of DFNA40

• We report here a dominant mutation in the GJB3 gene (D66del) in a family affected with peripheral neuropathy and sensorineural hearing impairment [37].
• Mutations in SOX10, a transcription modulator crucial in the development of the enteric nervous system (ENS), melanocytes and glial cells, are found in Shah-Waardenburg syndrome (WS4), a neurocristopathy that associates intestinal aganglionosis, pigmentation defects and sensorineural deafness [38].
• The much rarer Jervell-Lange-Nielsen syndrome (with marked QT prolongation and sensorineural deafness) arises when a child inherits mutant KVLQT1 or minK alleles from both parents [39].
• A gene for an autosomal dominant form of progressive sensorineural hearing loss (DFNA5) was previously assigned by us to a 15-cM region on chromosome 7p15 [40].
• Defects in the human gene encoding DSPP cause inherited dentin defects, and these defects can be associated with bilateral progressive high-frequency sensorineural hearing loss [41].

Analytical, diagnostic and therapeutic context of DFNA40

• The hearing loss was characterized by a high-frequency sensorineural deficit, which necessitated hearing aids in six patients [42].
• The number of days of illness (symptoms) before hospitalization and institution of antibacterial treatment was not correlated with the development of sensorineural deafness [1].
• Correlation between antibodies to type II collagen and treatment outcome in bilateral progressive sensorineural hearing loss [43].
• On pure-tone audiometry, 19 patients were shown to have sensorineural hearing loss, 3 of whom had evidence of an added conductive element [44].
• Cochlear implants have dramatically changed the treatment and prognosis for patients with profound sensorineural hearing loss [45].

References