Orenay-Boyacioglu Seda, Coskunoglu Aysun, Caki Zerrin, Cam Fethi Sirri
Department of Medical Genetics, Faculty of Medicine, Adnan Menderes University, Aydin, Turkey.
Department of Medical Genetics, Faculty of Medicine, Celal Bayar University, Manisa, Turkey.
Biochem Genet. 2016 Aug;54(4):552-563. doi: 10.1007/s10528-016-9741-1. Epub 2016 May 14.
Glial cell line-derived neurotrophic factor (GDNF) plays a key role in early development of central auditory pathway and the inner ear. However, the auditory pathway studies of GDNF gene polymorphisms are scarce in the literature, and the studies especially associated with tinnitus are limited. Our study aimed to identify whether GDNF gene polymorphisms play any roles in the pathophysiology of tinnitus by investigating the relationship between tinnitus and GDNF polymorphisms. A total of 52 patients with chronic tinnitus and ages ranging from 18 to 55 were admitted to the Ear-Nose-Throat outpatient clinic of Celal Bayar University Medical Faculty Hospital of Manisa, Turkey and constituted the study group. Another 42 patients of the same age range, without tinnitus symptoms and lacking any systemic disease, were also admitted to the clinic and formed the control group. The tympanometric, audiological, and psychoacoustic assessments of the subjects were performed. Deoxyribonucleic acid samples obtained using venous blood taken for routine inspections were used to investigate GDNF gene polymorphisms (rs884344, rs3812047, and rs1110149) by polymerase chain reaction-based restriction fragment length polymorphism method. No correlation could be detected between GDNF rs884344 and rs3812047 polymorphisms and subjects with tinnitus (p > 0.05). Heterozygosity was significantly lower for GDNF rs1110149 polymorphism in tinnitus subjects compared to the controls (p < 0.05). However, the allele frequencies for all 3 polymorphisms were not significantly different between tinnitus and control groups (p > 0.05). Failure to detect correlations between tinnitus and GDNF gene polymorphisms suggests this may be due to the fact that the GDNF gene has a variable expression pattern in different tissues and pathologies. Therefore, the study should be improved and its scope should be expanded by including a larger group of patients and different tissues to investigate the expression pattern of GDNF.
胶质细胞源性神经营养因子（GDNF）在中枢听觉通路和内耳的早期发育中起关键作用。然而，关于GDNF基因多态性的听觉通路研究在文献中较为少见，尤其是与耳鸣相关的研究有限。我们的研究旨在通过调查耳鸣与GDNF多态性之间的关系，确定GDNF基因多态性在耳鸣的病理生理学中是否起作用。共有52例年龄在18至55岁之间的慢性耳鸣患者被收治于土耳其马尼萨市切拉尔·贝亚尔大学医学院医院的耳鼻喉科门诊，构成研究组。另外42例年龄范围相同、无耳鸣症状且无任何系统性疾病的患者也被收治于该门诊，组成对照组。对受试者进行了鼓室图、听力学和心理声学评估。使用用于常规检查采集的静脉血获得的脱氧核糖核酸样本，通过基于聚合酶链反应的限制性片段长度多态性方法研究GDNF基因多态性（rs884344、rs3812047和rs1110149）。未检测到GDNF rs884344和rs3812047多态性与耳鸣患者之间存在相关性（p>0.05）。与对照组相比，耳鸣患者中GDNF rs1110149多态性的杂合度显著降低（p<0.05）。然而，耳鸣组和对照组之间所有3种多态性的等位基因频率无显著差异（p>0.05）。未检测到耳鸣与GDNF基因多态性之间的相关性，这可能是由于GDNF基因在不同组织和病理状态下具有可变的表达模式。因此，应扩大研究范围，纳入更多患者和不同组织，以研究GDNF的表达模式，从而改进该研究。
