The dopamine b-hydroxylase 19 bp insertion/deletion polymorphism was associated with first-episode but not medicated chronic schizophrenia

J Psychiatr Res. 2012 Jun;46(6):733-7. doi: 10.1016/j.jpsychires.2012.02.016. Epub 2012 Mar 24.


Background: Numerous studies report dysfunctional dopaminergic and noradrenergic neurotransmission in the pathogenesis of schizophrenia. Dopamine beta-hydroxylase (DBH) is an intracellular enzyme catalyzing the conversion of dopamine to noradrenaline. Functional polymorphisms have been reported in the promoter region of DBH gene, including a 19 bp insertion/deletion polymorphism. The purpose of this study was to investigate whether there was an association between the functional polymorphism (DBH5'-Ins/Del) and schizophrenia in a Han Chinese population.

Methods: This polymorphism was genotyped in 221 first-episode schizophrenics, 360 chronic schizophrenics and 318 healthy controls using a case-control design. We assessed their psychopathology using the Positive and Negative Syndrome Scale (PANSS).

Results: We showed that the DBH5'-Ins/Del deletion (Del) allelic and genotypic frequencies were significantly lower in controls than first-episode of schizophrenics (FES) (both p < 0.001), but controls were not different from chronic schizophrenics. Furthermore, the PANSS positive symptom and total scores were significantly higher in FES with the Del/Del genotype than those with Ins/Del and Ins/Ins genotypes (all p < 0.05).

Conclusions: The DBH5'-Ins/Del polymorphism may play a role in susceptibility to the positive symptoms of FES and to these FES not progressing on to chronic schizophrenia.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Adolescent
  • Adult
  • Age Factors
  • Antipsychotic Agents / therapeutic use
  • Case-Control Studies
  • Dopamine beta-Hydroxylase / genetics*
  • Female
  • Gene Frequency
  • Genetic Predisposition to Disease*
  • Genotype
  • Humans
  • Logistic Models
  • Male
  • Middle Aged
  • Polymorphism, Genetic / genetics*
  • Psychiatric Status Rating Scales
  • Schizophrenia / drug therapy
  • Schizophrenia / genetics*
  • Sequence Deletion / genetics*
  • Young Adult


  • Antipsychotic Agents
  • Dopamine beta-Hydroxylase