eNOS gene Glu298Asp variant confer risk in sudden sensorineural hearing loss

Abstract

Background: Sudden sensorineural hearing loss (SSNHL) causes the loss of hearing of 30 dB or greater on at least three contiguous frequencies. It is known to be a multifactorial disease which the exact cause is unknown, rendering it as an idiopathic disorder of patients.

Aims/objectives: This study aims to shed further light on pathogenesis of this disease by studying the association between eNOS gene Glu298Asp polymorphism and VDR gene FokI polymorphism with SSNHL in Iranian population.

Material and methods: This study involves a total of 77 cases and 100 controls, with patients inflicted with SSNHL categorized in case group and healthy subjects as control group. Genotyping of the VDR and eNOS genes was conducted by the polymerase chain reaction and restriction fragment length polymorphism (PCR-RFLP) method.

Results: Our results showed a statistically significant association between genotype frequencies of eNOS gene Glu298Asp polymorphism in case group compared to healthy individuals in the control group (p = .01). Also, TT genotype was significantly the most prevalent genotype in case group in comparison to control group (TT vs GT + GG, OR = 3.5; 95% CI = 1.18–11.79). On the other hand, analysis of VDR gene FokI polymorphism frequencies showed no statistically significant association with SSNHL.

Conclusions and significance: Our findings showed a significant association between the eNOS gene Glu298Asp polymorphism and SSNHL in the Iranian population; and “TT” genotype might be considered as a risk factor for SSNHL.

Chinese abstract

背景：突发性感音神经性听力损失（SSNHL）导致至少三个连续频率的30 dB或更高的听力损失。这是一种多因素疾病, 但其确切原因尚不清楚, 因此被看作一种特发性疾病。

目的：本研究旨在通过研究eNOS基因Glu298Asp多态性与VDR基因FokI多态性与伊朗人群中SSNHL的关系, 进一步阐明该病的发病机制。

材料与方法：本研究共纳入77例病例和100例对照, 病例组为SSNHL患者, 对照组为健康者。使用聚合酶链反应和限制性片段长度多态性（PCR-RFLP）方法进行VDR和eNOS基因的基因分型。

结果：我们的结果显示病例组中eNOS基因Glu298Asp多态性的基因型频率与对照组中的健康个体之间存在统计学显著相关性（p = .01）。此外, 与对照组相比, TT基因型在病例组中是显然最普遍的基因型（TT对GT + GG, OR = 3.5; 95％CI = 1.18-11.79）。另一方面, VDR基因FokI多态性频率的分析显示与SSNHL无统计学显着相关性。

结论和意义：我们的研究结果显示, eNOS基因Glu298Asp多态性与伊朗人群SSNHL之间存在显著相关性; “TT”基因型可以被认为是SSNHL的危险因素。

Keywords:

• eNOS
• VDR
• genetic variation
• SSNHL
• genetic association

Disclosure statement

No potential conflict of interest was reported by the authors.