Παρασκευή 17 Ιουνίου 2016

Association of TMTC2 With Human Nonsyndromic Sensorineural Hearing Loss.

Association of TMTC2 With Human Nonsyndromic Sensorineural Hearing Loss.

JAMA Otolaryngol Head Neck Surg. 2016 Jun 16;

Authors: Runge CL, Indap A, Zhou Y, Kent JW, King E, Erbe CB, Cole R, Littrell J, Merath K, James R, Rüschendorf F, Kerschner JE, Marth G, Hübner N, Göring HH, Friedland DR, Kwok WM, Olivier M

Abstract
Importance: Sensorineural hearing loss (SNHL) is commonly caused by conditions that affect cochlear structures or the auditory nerve, and the genes identified as causing SNHL to date only explain a fraction of the overall genetic risk for this debilitating disorder. It is likely that other genes and mutations also cause SNHL.
Objective: To identify a candidate gene that causes bilateral, symmetric, progressive SNHL in a large multigeneration family of Northern European descent.
Design, Setting, and Participants: In this prospective genotype and phenotype study performed from January 1, 2006, through April 1, 2016, a 6-generation family of Northern European descent with 19 individuals having reported early-onset hearing loss suggestive of an autosomal dominant inheritance were studied at a tertiary academic medical center. In addition, 179 unrelated adult individuals with SNHL and 186 adult individuals reporting nondeafness were examined.
Main Outcomes and Measures: Sensorineural hearing loss.
Results: Nine family members (5 women [55.6%]) provided clinical audiometric and medical records that documented hearing loss. The hearing loss is characterized as bilateral, symmetric, progressive SNHL that reached severe to profound loss in childhood. Audiometric configurations demonstrated a characteristic dip at 1000 to 2000 Hz. All affected family members wear hearing aids or have undergone cochlear implantation. Exome sequencing and linkage and association analyses identified a fully penetrant sequence variant (rs35725509) on chromosome 12q21 (logarithm of odds, 3.3) in the TMTC2 gene region that segregates with SNHL in this family. This gene explains the SNHL occurrence in this family. The variant is also associated with SNHL in a cohort of 363 unrelated individuals (179 patients with confirmed SNHL and 184 controls, P = 7 × 10-4).
Conclusions and Relevance: A previously uncharacterized gene, TMTC2, has been identified as a candidate for causing progressive SNHL in humans. This finding identifies a novel locus that causes autosomal dominant SNHL and therefore a more detailed understanding of the genetic basis of SNHL. Because TMTC2 has not been previously reported to regulate auditory function, the discovery reveals a potentially new, uncharacterized mechanism of hearing loss.

PMID: 27311106 [PubMed - as supplied by publisher]



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[Protective effect of peperphentonamine injection through the otocyst against gentamicin- induced cochlear damage in guinea pigs].

Related Articles

[Protective effect of peperphentonamine injection through the otocyst against gentamicin- induced cochlear damage in guinea pigs].

Nan Fang Yi Ke Da Xue Xue Bao. 2016 Apr;36(4):557-61

Authors: Li BB, Wu J, Chen J, Chen H, Li YH

Abstract
OBJECTIVE: To explore the relationship of gentamicin-induced cochlear damage with autophagy-related protein LC3, beclin1, Na(+-)K(+-)2Cl(-) cotransporter (NKCC1) mRNA and endothelin-1 (ET-1), and investigate the protective mechanism of PPTA against gentamicin-induced cochlear damage.
METHODS: Sixty guinea pigs were randomly divided into control group (with saline and artificial perilymph injections), model group (with gentamicin and artificial perilymph injections), concurrent treatment group (with gentamicin and PPTA injections), model control group (with artificial perilymph injection 7 days after gentamicin injection) and delayed treatment group (with PPTA injection 7 days after gentamicin injection). Saline and gentamicin (160 mg/kg) were injected intraperitoneally, and artificial perilymph and PPTA were injected into the otocysts on a daily basis for 7 consecutive days. Hearing impairment of the guinea pigs was analyzed with ABR, and the protein expressions of beclin1 and LC3 in cochlear tissue were tested. The expression of NKCC1 mRNA was detected with RT-PCR, and the expression of ET-1 was detected immunohistochemically.
RESULTS: The ABR thresholds in the model group and model control group were similar (P>0.05) , but significantly higher than those in the other 3 groups (P<0.05); the threshold was significantly lower in concurrent treatment group than in delayed treatment group (P<0.05). Compared with those in the other 4 groups, the expressions of LC3 II, beclin1, and NKCC1 mRNA were significantly increased in the model group (P<0.05); and those in delayed treatment group were significantly lower than those in the model control group (P<0.05). The expressions of ET-1 in the Corti organ, striavascularis and spiral ganglion were significantly higher in the model group but significantly lower in the control group than those in the other 4 groups; ET-1 expression was significantly lower in delayed treatment group than in the model control group.
CONCLUSION: PPTA offers protection against gantamicin-induced cochlear damage in guinea pigs by inhibiting cell autophagy and suppressing of NKCC1 and ET-1 expressions. Early intervention with PPTA produces better therapeutic effect, suggesting that gantamicin causes irreversible injury of the auditory cells.

PMID: 27113187 [PubMed - indexed for MEDLINE]



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Comprehensive handbook of pediatric audiology - second edition.

Comprehensive handbook of pediatric audiology - second edition.

Int J Audiol. 2016 Jun 16;:1-2

Authors: Flynn T

PMID: 27309404 [PubMed - as supplied by publisher]



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Comprehensive handbook of pediatric audiology - second edition

10.1080/14992027.2016.1195020<br/>Traci Flynn

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Comprehensive handbook of pediatric audiology - second edition.

Comprehensive handbook of pediatric audiology - second edition.

Int J Audiol. 2016 Jun 16;:1-2

Authors: Flynn T

PMID: 27309404 [PubMed - as supplied by publisher]



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via IFTTT

Comprehensive handbook of pediatric audiology - second edition.

Comprehensive handbook of pediatric audiology - second edition.

Int J Audiol. 2016 Jun 16;:1-2

Authors: Flynn T

PMID: 27309404 [PubMed - as supplied by publisher]



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via IFTTT

Comprehensive handbook of pediatric audiology - second edition

10.1080/14992027.2016.1195020<br/>Traci Flynn

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