Estudo da associação entre polimorfismos genéticos no gene Melatonin Receptor type 1a (MTNR1A) e bruxismo do sono

• Ano de defesa: 2021
• Autor(a) principal: Gaio, Daniella Cristina
• Tipo de documento: Dissertação
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Universidade Positivo; Brasil; Odontologia; PPG1; UP
• Palavras-chave em Português: Odontologia; Bruxismo; Bruxismo do sono; Genética; Polimorfismo genético; CNPQ::CIENCIAS DA SAUDE::ODONTOLOGIA
• Link de acesso: https://repositorio.cruzeirodosul.edu.br/handle/123456789/4072

Introduction: Bruxism is characterized by the activity of the masticatory muscles that can happen during sleep (Sleep Bruxism, SB) and / or during wakefulness (Awake Bruxism, AB). Its etiology is multifactorial, with the participation of several physiological and psychosocial factors, in addition to external factors, but studies indicate that the genetic background of the individual seems to have an important role in the evolution of this condition. Regarding the genetic factor, several genes have been associated with Bruxism and other genes, although they have not been investigated, deserve attention. One such gene is the gene encoding the Melatonin Receptor called melatonin receptor type 1A (MTNR1A). Objective: investigate the association between the MTNR1A gene and SB in an adult population. Materials and Method: A total of 48 adults of both sexes were submitted to clinical examination by the RDC/TMD (Research Diagnostic Criteria for Temporomandibular Disorders) following the recommendations proposed by the American Academy of Sleep Medicine (AASM). Questionnaire for assessing Bruxism and Polysomnography exam were performed in all individuals. DNA samples were collected and three SNPs in the MTNR1A gene (rs13140012, rs6553010 and rs6847693) were selected and genotyped using the real-time PCR technique. Data were analyzed using the Epi Info 3.5.7 and Stata programs (StataCorp, College Station, TX, USA, version 11) considering the allelic, genotypic, dominant or recessive models. PLINK 1.07 (https://zzz.bwh.harvard.edu/plink/index.shtml) program was used for haplotype analysis. The Hardy-Weinberg balance was assessed using the chi-square test for each polymorphism included in this study. The level of statistical significance was set at 95% (p <0.05). Results: 48 individuals (27 men and 21 women, aged between 21 and 80 years) were included in the study. 17 individuals diagnosed with SB (11 men and 6 women) were included in the affected group. Another 31 individuals (16 men and 15 women) were diagnosed no bruxism and were included in the unaffected group. Regarding genetic polymorphisms, all were in Hardy-Weinberg equilibrium, and the chi-square for rs6553010, rs13140012 and rs6847693 were 2.2, 0.67 and 2.12, respectively. No associations were found between SB and the SNPs studied both in the genotypic model and in the allelic, dominant and recessive models (p> 0.05). Haplotype genetic analysis also did not reveal any association between SNPs and SB (p> 0.05). Conclusion: Since the tests used for the diagnosis of SB are gold standard clinical and laboratory tests, the obtained results are suggestive that there is no involvement of the MTNR1A gene in the etiology of SB in the studied population.