Genetic Polymorphisms and Susceptibility to Sudden Sensorineural Hearing Loss: A Systematic Review

Abstract

Background: Recently, genetic factors have been considered as an important risk factor for sudden sensorineural hearing loss (SSNHL). Many studies analyzed the association between SSNHL and polymorphisms. However, most of them gave inconclusive results. Key Message: We performed a systematic review to find out the association between polymorphisms and susceptibility to SSNHL. Finally, 47 studies involving 5,230 SSNHL patients and 68 genes were included for analysis and discussion of results. Polymorphisms in 26 genes have been suggested to be correlated with the susceptibility to SSNHL. Summary: Although a great number of studies support that polymorphisms in genes are associated with susceptibility to SSNHL, we need large multicenter studies, which evaluate multiple single nucleotide polymorphisms in SSNHL patients, to find real genetic risk factors for susceptibility to SSNHL. This is very helpful in designing more effective prevention and treatment strategies for patients with SSNHL.

Genetic Polymorphisms in Sudden Sensorineural Hearing Loss: An Update

“…28 Data in the current literature show that several genetic polymorphisms correlated with oxidative stress, inflammation, thrombosis, and blood vessel permeability are associated to SSNHL predisposition and development. 10,12,20,24,28,36,37,40,41 On the basis of this evidence, it could be hypothesized that genetic factors could play a role in maintaining the delicate balance between ROS and antioxidants, pro-inflammatory and anti-inflammatory factors, proaggregants, and antiaggregants; since the balance among these factors is important for the inner ear homeostasis, their disruption could be a factor contributing to the ISSNHL onset. Furthermore, a possible link between SSNHL and major cardiovascular diseases, such as stroke and myocardial infarction, has been previously highlighted.…”

“…34 The identification of the ISSNHL susceptibility genes could be important in the prediction of the treatment outcome and possibly could help physicians in choosing the most suitable therapeutic option (ie, tailored therapy). 10 The fact that the majority of the available studies in the literature used small sample sizes to assess specific ethnic groups suggests that additional research is needed to elucidate specific arguments in order to better understand the relationship between ISSNHL and genetic polymorphisms. Nowadays, it is only possible to speculate on the clinical significance of genetic polymorphisms in patients affected by SSNHL: Further studies are necessary in order to identify reliable genetic risk factors for SSNHL predisposition.…”

“…1 Several pathophysiological theories of idiopathic SSNHL (ISSNHL) have been proposed, such as inner ear viral infection, 2,3 inner ear vascular damage, 4 endolymphatic hydrops, destruction of the cochlear labyrinthine membranes, 5,6 immune-mediated disorders, 7,8 and electrolyte imbalance of intracochlear fluids. 9 Various genetic factors leading to SSNHL have also been addressed, 10 although there is little evidence in the literature for a genetic origin of SSNHL. 11 However, the influence of some genes, such as methylenetetrahydrofolate reductase, 12,13 protein kinase C eta, 14 complement factor H 15 , and lymphotoxin a ,16 on the SSNHL onset has been already reported.…”

“…The majority of data in the literature refers to genes related to inner ear microvascular disease and/or endothelial dysfunction or to inner ear inflammation and/or oxidative stress. 10 The present article aimed to review the current literature and to investigate the association between genetic polymorphisms and SSNHL.…”

Hipoacusia neurosensorial súbita, el gran dilema de la otorrinolaringología. Una revisión de la literatura

“…14,66 La prevalencia se calcula alrededor de 5 a 20 casos por 100 000, o cerca de 4 000 a 66 000 casos cada año en Estados Unidos, 5 a 30 por 100 000 en Reino Unido y 160 casos por 100 000 en Alemania 26,61 la incidencia total mundial es difícil de calcular debido a que la mayoría de casos que resuelven espontáneamente sin requerimiento de monitoreo, 37 sin embargo Cao Z. y cols calculan un aproximado de 0.005% a 0.02%. 10 Los estudios poblacionales establecen el rango etario en un amplio margen, entre 25 y 60 años, con un pico de importancia entre 45 y 59 años, sin distinción de género. 26,37,58 En la población adolescente e infantil se estima una prevalencia 3.5% de la prevalencia en población adulta.…”