title: Polymorphisms of iodothyronine deiodinases (DIO1, DIO3) genes are not associated with recurrent depressive disorder.
abstract: BACKGROUND
  Depressive disorder is characterized by disturbances in the hypothalamic-pituitary-thyroid (HPT) axis and in the metabolism of thyroid hormones (TH). The evidence for changes in TH levels is observed in human sera and cerebrospinal fluid as well as in animal model studies. Iodothyronine deiodinases (DIOs) type 1, 2 and 3 (DIO1, DIO2, DIO3) are important enzymes for the synthesis and determination of TH concentration. This study aims to examine the link between recurrent depressive disorders (rDD) and two functionally known polymorphisms DIO1a-C/T (rs11206244) and DIO1b-A/G (rs12095080) within the DIO1 gene encoding DIO1 and two polymorphisms DIO3-C/T (rs17716499), DIO3-A/C (rs7150269) within the DIO3 gene encoding DIO3.
  
  
  METHODS
  Both variants were genotyped in 254 rDD patients and 197 healthy subjects using polymerase chain reaction. Basic methods and statistical analyses were used to estimate genetic variants in the risk of the disease.
  
  
  RESULTS
  No significant associations were found between the polymorphisms examined here and rDD. There were no significant associations between genotypes distribution and demographic/medical variables. Odds ratios (ORdis) and corresponding 95% confidence interval (95% CI) were calculated, for example: for CC genotype of DIO1a C/T (ORdis=0.86, 95% CI: 0.59, 1.25).
  
  
  CONCLUSIONS
  Functional variants within the DIO1 gene, which affect TH levels and polymorphisms in DIO3, are not confirmed to be associated with rDD. Nevertheless, considering previous data which indicate that the DIO1 gene is related to the depression, further studies on a larger sample size are recommended.
authors.affiliation: Department of Pneumology and Allergy, Medical University of Łódź, Poland. Electronic address: galeckaela@wp.pl.
authors.forename: Elżbieta
authors.initials: E
authors.lastname: Gałecka
authors.affiliation: Department of Adult Psychiatry, Medical University of Łódź, Poland.
authors.forename: Monika
authors.initials: M
authors.lastname: Talarowska
authors.affiliation: Deakin University IMPACT Strategic Research Centre, Deakin University, School of Medicine, Barwon Health, Geelong, Australia; Department of Psychiatry, Chulalongkorn University, Bangkok, Thailand; Health Sciences Graduate Program, Health Sciences Center, State University of Londrina, Londrina, Brazil.
authors.forename: Michael
authors.initials: M
authors.lastname: Maes
authors.affiliation: Graduate Institute of Neural and Cognitive Sciences, School of Medicine, China Medical University, Taichung, Taiwan; Department of Psychiatry and Mind-Body Research Center (MBI-Lab), China Medical University Hospital, Taichung, Taiwan.
authors.forename: Kuan-Pin
authors.initials: KP
authors.lastname: Su
authors.affiliation: Department of Pneumology and Allergy, Medical University of Łódź, Poland.
authors.forename: Paweł
authors.initials: P
authors.lastname: Górski
authors.affiliation: Department of Medical Biochemistry, Medical University of Lodz, Łódź, Poland.
authors.forename: Janusz
authors.initials: J
authors.lastname: Szemraj
mesh_terms: D000328:Adult; D004268:DNA-Binding Proteins / Q000235:genetics*; D003863:Depression / Q000235:genetics*; D003865:Major Depressive Disorder / Q000235:genetics*; D005260:Female; D020022:Genetic Predisposition to Disease; D005838:Genotype; D006801:Humans; D007453:Iodide Peroxidase / Q000235:genetics*; D008297:Male; D020641:Polymorphism, Single Nucleotide / Q000235:genetics*; D012306:Risk; D013963:Thyroid Hormones / Q000235:genetics
chemical_list: C518584:DIDO1 protein, human; D004268:DNA-Binding Proteins; D013963:Thyroid Hormones; C117274:iodothyronine deiodinase type III; D007453:Iodide Peroxidase
keywords: Polymorphism; Recurrent depressive disorder; Type 1 and 3 iodothyronine deiodinases