title: Serotonin transporter gene variation is a risk factor for sudden infant death syndrome in the Japanese population.
abstract: OBJECTIVE
  Serotonin (5-HT) in the nervous system is a major factor in facilitation of the brain center for respiration. Variations in the promoter region of the 5-HT transporter (5-HTT) gene have been shown to potentially regulate 5-HT activity in the brain. Therefore, we aimed to identify the possibility that specific allele variants of the 5-HTT gene can be found as a genetic background for sudden infant death syndrome (SIDS).
  
  
  METHODS
  Polymorphisms in the 5' regulatory region of the 5-HTT gene were determined in genomic DNA obtained from 27 SIDS victims and 115 age-matched health control participants.
  
  
  RESULTS
  There were significant differences in genotype distribution and allele frequency of the 5-HTT promoter gene between SIDS victims and age-matched control participants. The L and XL alleles were more frequently found in SIDS victims than in age-matched control participants.
  
  
  CONCLUSIONS
  Efficiency in the transportation of 5-HTT with the L allele is known to be higher than that with the S allele. The excitatory function by 5-HT is considered to be lower in the respiratory center of individuals with the L allele compared with those with S allele. The XL allele variant has shown another novel biological risk factor for SIDS.
authors.affiliation: Department of Pediatrics, Dokkyo University, School of Medicine, Koshigaya Hospital, Saitama, Japan.
authors.forename: N
authors.initials: N
authors.lastname: Narita
authors.forename: M
authors.initials: M
authors.lastname: Narita
authors.forename: S
authors.initials: S
authors.lastname: Takashima
authors.forename: M
authors.initials: M
authors.lastname: Nakayama
authors.forename: T
authors.initials: T
authors.lastname: Nagai
authors.forename: N
authors.initials: N
authors.lastname: Okado
mesh_terms: D002352:Carrier Proteins / Q000235:genetics*; D005787:Gene Frequency / Q000235:genetics; D020022:Genetic Predisposition to Disease; D014644:Genetic Variation; D005838:Genotype; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D007564:Japan; D008562:Membrane Glycoproteins / Q000235:genetics*; D026901:Membrane Transport Proteins; D009419:Nerve Tissue Proteins; D011110:Polymorphism, Genetic; D012125:Respiratory Center / Q000502:physiology / Q000503:physiopathology; D012307:Risk Factors; D012701:Serotonin / Q000235:genetics*; D050486:Serotonin Plasma Membrane Transport Proteins; D013398:Sudden Infant Death / Q000175:diagnosis / Q000209:etiology* / Q000235:genetics
chemical_list: D002352:Carrier Proteins; D008562:Membrane Glycoproteins; D026901:Membrane Transport Proteins; D009419:Nerve Tissue Proteins; C493230:SLC6A4 protein, human; D050486:Serotonin Plasma Membrane Transport Proteins; D012701:Serotonin