title: The G619A Aa-nat gene polymorphism does not contribute to sleep time variation in the Brazilian population.
abstract: Genes involved in melatonin synthesis, such as Aa-nat, may be important for our understanding of diurnal preference and circadian rhythm disturbances in humans. In Japan, Hohjoh et al. reported increased allelic frequencies of the 619A allele of the G619A Aa-nat gene polymorphism in a sample of Delayed Sleep Phase Syndrome (DSPS) patients. The present study sought to analyze G619A polymorphism frequency in a Brazilian sample, including DSPS patients. We found almost no allelic variation for G619A polymorphism in our sample, except for two heterozygous samples out of 551. Our results leave open the question of whether there would be an association if there were some genetic variation in our population. It is important to analyze different ethnic groups in order to validate the effect of G619A polymorphism on sleep timing.
authors.affiliation: Department of Psychobiology/Sleep Institute, Universidade Federal de São Paulo, Rua Napoleão de Barros 925, Sao Paulo, SP 04024-002, Brazi.
authors.forename: Danyella Silva
authors.initials: DS
authors.lastname: Pereira
authors.forename: Mario
authors.initials: M
authors.lastname: Pedrazzoli
authors.forename: Bruna Del Vechio
authors.initials: Bdel V
authors.lastname: Koike
authors.forename: Fernando Mazzili
authors.initials: FM
authors.lastname: Louzada
authors.forename: Ana Amélia
authors.initials: AA
authors.lastname: Benedito-Silva
authors.forename: Alberto Remesar
authors.initials: AR
authors.lastname: Lopez
authors.forename: Sergio
authors.initials: S
authors.lastname: Tufik
mesh_terms: D000328:Adult; D001191:Arylamine N-Acetyltransferase / Q000235:genetics*; D001938:Brazil; D002940:Circadian Rhythm / Q000235:genetics*; D005260:Female; D006580:Genetic Carrier Screening; D006720:Homozygote; D006801:Humans; D008297:Male; D008550:Melatonin / Q000096:biosynthesis* / Q000235:genetics*; D016133:Polymerase Chain Reaction; D012150:Polymorphism, Restriction Fragment Length; D020641:Polymorphism, Single Nucleotide; D012890:Sleep / Q000502:physiology*
chemical_list: D001191:Arylamine N-Acetyltransferase; D008550:Melatonin