Polymorphisms in the 5-HTR2A gene related to obstructive sleep apnea syndrome

Vânia Belintani Piatto,Thiago Bittencourt Ottoni De Carvalho,Nely Silva Aragão De Marchi,Fernando Drimel Molina,José Victor Maniglia

doi:10.1590/s1808-86942011000300013

Abstract

Obstructive sleep apnea syndrome (OSAS) is one of the most complex disorders of sleep; it involves several genetic factors that contribute to the phenotype. Serotonin (5-HT) regulates a variety of visceral and physiological functions, including sleep. Gene 5-HTR2A polymorphisms may change the transcription of several receptors in the serotoninergic system, thereby contributing to OSAS. AimTo investigate the prevalence of T102C and -1438G/A polymorphisms in the 5-HTR2A gene of patients with and without OSAS. Material and MethodA molecular study of 100 index-cases and 100 controls of both genders. DNA was extracted from blood leukocytes samples and the regions that enclose both polymorphisms were amplified with PCR-RFLP. Study designA cross-sectional case study. ResultsThere was a significant prevalence of males in index cases compared to controls (p<0.0001). No significant genotypic differences between cases and controls were found in T102C polymorphisms (p=1.000). There were significant differences between the AA genotype of -1438G/A polymorphisms and patients with OSAS (OR:2.3; CI95%:1.20-4.38, p=0.01). ConclusionSerotonergic mechanisms may be related to OSAS. There were no differences in the prevalence of T102C polymorphisms in patients with OSAS and the control group. There is evidence of an association between the -1438G/A polymorphism and OSAS.

Highlights

The obstructive sleep apnea syndrome (OSAS) is a common disorder of sleep affecting from 2% to 4% of adult males
No significant genotypic differences between cases and controls were found in T102C polymorphisms (p=1.000).There were significant differences between the AA genotype of -1438G/A polymorphisms and patients with OSAS (OR:2.3; CI95%:1.20-4.38, p=0.01)
There were no differences in the prevalence of T102C polymorphisms in patients with OSAS and the control group

Summary

Introduction

The obstructive sleep apnea syndrome (OSAS) is a common disorder of sleep affecting from 2% to 4% of adult males It may be characterized by recurring sleep-induced pharyngeal airway collapse resulting in hypoxemia and hypercapnia.[1] Several genetic factors are probably involved, since there are many phenotypic components.[2,3,4,5]. Changes in central nervous control of upper airway muscles are considered an important component of this syndrome.[6] The genioglossus muscle is innervated by neurons that originate in the hypoglossal nucleus within the brainstem; contractions of this muscle during inspiration help ventilate the lungs and keep upper airways open during wakefulness and sleep.[7,8] Groups of serotonergic and noradrenergic cells may generate parallel patterns by stimulating directly the motor cells of the hypoglossal nerve, thereby regulating these dilating muscles. Activation of these cell groups increases the activity of the genioglossus muscle.[7,8,9]

Objectives

Methods

Results

Discussion

Conclusion