title: Association of monoamine-synthesizing genes with the depression tendency and personality in chronic fatigue syndrome patients.
abstract: OBJECTIVE
  Tyrosine hydroxylase (TH) and GTP cyclohydrolase I (GCH) are the rate-limiting enzymes for the biosynthesis of catecholamines and tetrahydrobiopterin (BH4), respectively. Since catecholamines and BH4 are thought to be involved in the pathophysiology of CFS, we explored the genetic factors that influence CFS development and examined the possible association between the SNPs of the TH and GCH genes and the various characteristics of CFS patients.
  
  
  METHODS
  After drawing venous blood from CFS patients and controls, genomic DNA was then extracted from whole blood in accordance with standard procedures. Digestion patterns of the PCR products were used for genotyping the SNPs of GCH (rs841; C+243T) and TH (rs10770141; C-824T). We also performed questionnaires consisting of fatigue-scale and temperament and character inventory scale (TCI) to CFS patients.
  
  
  RESULTS
  Our results demonstrated that the allele differences for the GCH and TH SNPs were not associated with CFS patients. We did find that the GCH gene with the C+243T polymorphism affected harm avoidance, while the TH gene with the C-824T polymorphism affected persistence in the CFS patients. The concept of persistence has been linked to specific personality, such as perfectionism, in CFS.
  
  
  CONCLUSIONS
  Our results suggest that the biosynthetic pathways of the monoamine neurotransmitters that are mediated by TH and GCH might be associated with the CFS clinical findings, because persistence is one of the typical personality traits observed in CFS and patients with major depressive disorder exhibit a higher harm avoidance score.
authors.affiliation: Department of Medical Science on Fatigue, Osaka City University, Graduate School of Medicine, Osaka, Japan.
authors.forename: Sanae
authors.initials: S
authors.lastname: Fukuda
authors.forename: Mieko
authors.initials: M
authors.lastname: Horiguchi
authors.forename: Kouzi
authors.initials: K
authors.lastname: Yamaguti
authors.forename: Yasuhito
authors.initials: Y
authors.lastname: Nakatomi
authors.forename: Hirohiko
authors.initials: H
authors.lastname: Kuratsune
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Ichinose
authors.forename: Yasuyoshi
authors.initials: Y
authors.lastname: Watanabe
mesh_terms: D002395:Catecholamines / Q000096:biosynthesis / Q000235:genetics*; D003863:Depression / Q000201:enzymology / Q000235:genetics*; D015673:Fatigue Syndrome, Chronic / Q000201:enzymology / Q000235:genetics*; D005260:Female; D006136:GTP Cyclohydrolase / Q000235:genetics*; D006801:Humans; D008297:Male; D010554:Personality Disorders / Q000201:enzymology / Q000235:genetics*; D020641:Polymorphism, Single Nucleotide; D011622:Pterins / Q000378:metabolism; D014446:Tyrosine 3-Monooxygenase / Q000235:genetics*
chemical_list: D002395:Catecholamines; D011622:Pterins; C011552:tetrahydropterin; D014446:Tyrosine 3-Monooxygenase; D006136:GTP Cyclohydrolase