title: Phosphoinositide cycle gene polymorphisms affect the plasma lipid profile in the Quebec Family Study.
abstract: BACKGROUND
  The small, dense LDL phenotype is associated with an increased cardiovascular disease risk. A genome-wide scan performed on 236 nuclear families of the Quebec Family Study (QFS) revealed a QTL for LDL-peak particle size (LDL-PPD) on the 17q21 region. Three positional candidates were identified in this region according to their implication in the phosphoinositide (PI) cycle: the myotubularin-related protein 4 (MTMR4), the phospholipase C, delta 3 (PLCD3), and the diacylglycerol kinase E (DGKE) genes.
  
  
  OBJECTIVE
  To test the association between MTMR4, PLCD3, and DGKE gene polymorphisms, LDL-PPD and plasma lipid parameters.
  
  
  METHODS
  Analyses were performed on 680 subjects of QFS. LDL-PPD was measured by gradient gel electrophoresis on non-denaturating 2-16% polyacrylamide gradient gels. Direct sequencing was performed to identify genetic variations within these genes.
  
  
  RESULTS
  The c.-754G>C, c.183G>A, and c.579C>A DGKE SNPs were significantly associated with higher plasma triglyceride levels (p=0.029, p=0.008, p=0.001, respectively). The c.508C>G and c.890T>G MTMR4 polymorphisms were associated with plasma total-cholesterol concentrations (p=0.02, p=0.02, respectively), while no association was observed with PLCD3 gene polymorphisms.
  
  
  CONCLUSIONS
  The c.579C>A DGKE gene polymorphism is associated with plasma triglyceride levels, while MTMR4 SNPs seem to predict variations in plasma cholesterol levels.
authors.affiliation: CRML, CHUQ Research Center, 2705 Laurier Boulevard, Que., Canada.
authors.forename: Guillaume
authors.initials: G
authors.lastname: Dolley
authors.forename: Benoît
authors.initials: B
authors.lastname: Lamarche
authors.forename: Jean-Pierre
authors.initials: JP
authors.lastname: Després
authors.forename: Claude
authors.initials: C
authors.lastname: Bouchard
authors.forename: Louis
authors.initials: L
authors.lastname: Pérusse
authors.forename: Marie-Claude
authors.initials: MC
authors.lastname: Vohl