title: TPH1 A218 allele is associated with suicidal behavior in Turkish population.
abstract: BACKGROUND
  Serotonergic dysfunction is implicated in depression, psychiatric disorders and suicidal behaviors. The first and rate-limiting step in the synthesis of serotonin is catalyzed by tryptophan hydroxylase (TPH) which is encoded by TPH1 and THP2 genes. Genetic association studies have revealed contradictory results about the effect of the TPH1 A218C (rs1800532) polymorphism on suicidal behavior in different populations.
  
  
  METHODS
  In this study, we investigated A218C polymorphism in 109 suicide attempters and 98 healthy controls. Socio-demographic characteristics of participants were obtained through questionnaire. DNA was extracted from peripheral blood and genotyping was performed by Real Time PCR. Fisher's exact test was used to evaluate the significance of the difference among the independent variables. Hardy-Weinberg equilibrium was tested using Pearson's goodness-of-fit chi-squared test.
  
  
  RESULTS
  The frequency of A allele was significantly higher in suicide attempters than controls (46.33% vs. 35.71%, p=0.0357). However, there were no differences in genotype frequencies of this locus between participants having attempted suicide and controls (p>0.05). Among males, frequencies of CC genotype and C allele were found to be significantly higher in controls (p=0.0125, p=0.0298). With regard to the female subjects and female controls, no significant association was detected between suicidal behavior and genotype/allele frequencies (p>0.05).
  
  
  CONCLUSIONS
  Our results provide evidence that A allele of TPH1 A218C polymorphism may be associated with suicidal behavior in Turkish population.
authors: Ege University, School of Medicine, Department of Forensic Medicine, Bornova, Izmir 35100, Turkey.
authors: Onur
authors: O
authors: Beden
authors: Ege University, School of Medicine, Department of Forensic Medicine, Bornova, Izmir 35100, Turkey.
authors: Ender
authors: E
authors: Senol
authors: Ege University, School of Medicine, Department of Medical Biochemistry, Bornova, Izmir 35100, Turkey.
authors: Sevcan
authors: S
authors: Atay
authors: Ege University, School of Medicine, Department of Medical Biochemistry, Bornova, Izmir 35100, Turkey.
authors: Handan
authors: H
authors: Ak
authors: Ege University, School of Medicine, Department of Psychiatry, Bornova, Izmir 35100, Turkey.
authors: Ayse Ender
authors: AE
authors: Altintoprak
authors: Ege University, School of Medicine, Department of Emergency Medicine, Bornova, Izmir 35100, Turkey.
authors: Guclu Selahattin
authors: GS
authors: Kiyan
authors: Ege University, School of Medicine, Department of Psychiatry, Bornova, Izmir 35100, Turkey.
authors: Buket
authors: B
authors: Petin
authors: Ege University, School of Medicine, Department of Psychiatry, Bornova, Izmir 35100, Turkey.
authors: Utku
authors: U
authors: Yaman
authors: Ege University, School of Medicine, Department of Medical Biochemistry, Bornova, Izmir 35100, Turkey. Electronic address: hhakan.aydin@gmail.com.
authors: Hikmet Hakan
authors: HH
authors: Aydin
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D005260:Female; D020022:Genetic Predisposition to Disease; D005838:Genotype; D006801:Humans; D008297:Male; D008875:Middle Aged; D011110:Polymorphism, Genetic / Q000235:genetics*; D013406:Suicide, Attempted; D014365:Tryptophan Hydroxylase / Q000235:genetics*; D014421:Turkey; D055815:Young Adult
chemical_list: D014365:Tryptophan Hydroxylase
keywords: Polymorphism; Serotonin; Suicide; Tryptophan hydroxylase