PRODH rs450046 and proline x COMT Val¹⁵⁸ Met interaction effects on intelligence and startle in adults with 22q11 deletion syndrome

Psychopharmacology (Berl). 2015 Sep;232(17):3111-22. doi: 10.1007/s00213-015-3971-5. Epub 2015 Jun 12.


Rationale: 22q11 deletion syndrome (22q11DS) is associated with an increased risk for psychotic disorders, suggesting a relationship between genotypes and the pathophysiology of psychotic disorders. Two genes in the deleted region, catechol-O-methyl-transferase (COMT) and proline dehydrogenase (oxidase) 1 (PRODH), contain polymorphisms associated with neuropsychiatric phenotypes.

Objectives: Here, we explored the association between polymorphisms and full-scale intelligence (FSIQ), startle reactivity (SR) and prepulse inhibition (PPI) in adults with 22q11DS.

Methods: Forty-five adults with 22q11DS were genotyped for PRODH rs450046, rs372055 and COMT Val(158)Met. Plasma proline levels, FSIQ, SR and PPI were measured.

Results: Thirty-five percent of the subjects were hyperprolinemic with a median proline value of 456 μmol/L. C allele carriers of PRODH rs450046 had a lower FSIQ compared to T allele carriers, indicating the C allele to be a risk allele (C allele: mean FSIQ 60.2 (sd 8.7); T allele: mean FSIQ 73.7 (sd 11.5); F 1,43 = 7.59; p = 0.009; partial η (2) = 0.15). A significant interaction effect of proline levels and COMT Val(158)Met genotype was found for SR (F 1,16 = 7.9; p = 0.01; partial η (2) = 0.33), but not for PPI and FSIQ. In subjects with hyperprolinemia, the COMT Val(158)Met genotype effect on SR was stronger than in subjects with normal proline levels.

Conclusions: Overall, these data provide further evidence for the risk effect of elevated proline levels combined with the COMT Met allele and support the possibilities of using 22q11DS as a model to investigate genotype effects on psychiatric disorders.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • 22q11 Deletion Syndrome / genetics*
  • 22q11 Deletion Syndrome / psychology*
  • Adult
  • Biomarkers
  • Catechol O-Methyltransferase / genetics*
  • Diagnostic and Statistical Manual of Mental Disorders
  • Female
  • Genotype
  • Heterozygote
  • Humans
  • Intelligence / genetics*
  • Intelligence Tests
  • Male
  • Middle Aged
  • Polymorphism, Genetic / genetics
  • Proline / blood
  • Proline Oxidase / genetics*
  • Psychotropic Drugs / therapeutic use
  • Reflex, Startle / genetics*
  • Schizophrenia / genetics
  • Young Adult


  • Biomarkers
  • Psychotropic Drugs
  • Proline
  • Proline Oxidase
  • PRODH protein, human
  • COMT protein, human
  • Catechol O-Methyltransferase