title: Association study of 90 candidate gene polymorphisms in panic disorder.
abstract: OBJECTIVE
  In the present investigation we screened a large number of single nucleotide polymorphisms in the genes relevant to the neurobiology of anxiety for their association with panic disorder (PD).
  
  
  METHODS
  The study sample included 127 patients with PD and 146 healthy control subjects. Using Arrayed Primer Extension technology we genotyped 90 polymorphisms in 21 candidate genes of serotonin, cholecystokinin, dopamine and opioid neurotransmitter systems. The association and haplotype analyses were performed in the whole group (PD-all) and in the subgroups of PD comorbid with major depression (PD-comorbid, n = 60) and without any comorbidity (PD-pure, n = 42).
  
  
  RESULTS
  From the set of 90 polymorphisms, eight single nucleotide polymorphism markers in eight genes displayed at least a nominal association with any of the studied PD phenotype subgroups. Several polymorphisms of cholecystokinin, serotonin and dopamine systems were associated with PD-all and/or PD-comorbid phenotypes, while pure PD was associated only with HTR2A receptor 102T-C (P = 0.01) and DRD1 receptor -94G-A (P = 0.02) polymorphisms. Haplotype analysis supported an association of the cholecystokinin gene TG haplotype with the PD-all group (P = 0.04), whereas DRD1 receptor CAA and HTR2A receptor AT haplotypes were associated with a lower risk for PD-pure phenotype (P = 0.03 and P = 0.04, respectively).
  
  
  CONCLUSIONS
  The study results suggest that genetic variants of several candidate genes of neurotransmitter systems, each of a minor individual effect, may contribute to the susceptibility to PD. Our data also indicate that genetic variability may have a distinctive influence on pure and comorbid phenotypes of PD.
authors.affiliation: Department of Psychiatry, University of Tartu, Tartu 50417, Estonia. Eduard.Maron@kliinikum.ee
authors.forename: Eduard
authors.initials: E
authors.lastname: Maron
authors.forename: Tiit
authors.initials: T
authors.lastname: Nikopensius
authors.forename: Sulev
authors.initials: S
authors.lastname: Kõks
authors.forename: Signe
authors.initials: S
authors.lastname: Altmäe
authors.forename: Evelin
authors.initials: E
authors.lastname: Heinaste
authors.forename: Kristel
authors.initials: K
authors.lastname: Vabrit
authors.forename: Veronika
authors.initials: V
authors.lastname: Tammekivi
authors.forename: Pille
authors.initials: P
authors.lastname: Hallast
authors.forename: Kati
authors.initials: K
authors.lastname: Koido
authors.forename: Ants
authors.initials: A
authors.lastname: Kurg
authors.forename: Andres
authors.initials: A
authors.lastname: Metspalu
authors.forename: Eero
authors.initials: E
authors.lastname: Vasar
authors.forename: Veiko
authors.initials: V
authors.lastname: Vasar
authors.forename: Jakov
authors.initials: J
authors.lastname: Shlik
mesh_terms: D002766:Cholecystokinin / Q000235:genetics; D015897:Comorbidity; D004247:DNA / Q000097:blood / Q000235:genetics / Q000302:isolation & purification; D017931:DNA Primers; D003866:Depressive Disorder / Q000235:genetics; D005838:Genotype; D006801:Humans; D020411:Oligonucleotide Array Sequence Analysis; D016584:Panic Disorder / Q000235:genetics*; D011110:Polymorphism, Genetic; D011954:Receptors, Dopamine / Q000235:genetics; D011985:Receptors, Serotonin / Q000235:genetics; D012016:Reference Values
chemical_list: D017931:DNA Primers; D011954:Receptors, Dopamine; D011985:Receptors, Serotonin; D004247:DNA; D002766:Cholecystokinin