Effect Of DRD4 Receptor-616 C/G Polymorphism On Cerebral Blood Flow In Pediatric Primary Nocturnal Enuresis Patients,A MR Perfusion Imaging Study Using Pulsed Arterial Spin Labeling Technique

Objective :To determine whether the-616 C/G single nucleotide polymorphism(SNP)in the dopamine D4 receptor(DRD4)promoter rs747302 is associated with abnormal cerebral blood flow(CBF)in children that suffer from primary nocturnal enuresis(PNE)using arterial spin labeling(ASL)methodology.Methods :Genomic and ASL imaging data were obtained from 83 PNE pediatric patients and 86 healthy controls.SNP of rs747302 was genotyped.ASL imaging data were collected on a 3.0-Tesla MR scanner,CBF data were calculated and post processed with the VBM8 software package.CBF were compared between different group(PNE/control)and genotype(C/G).Results :Main effect of genotype in the right thalamus and group-genotype interaction in the left medial prefrontal cortex(m PFC)on CBF were found(P<0.05,FDR corrected).The brain regions with significant interaction effects on left m PFC were extracted,and CBF values in brain area were calculated.Post-Hoc test was performed on CBF mean of different genotype children in PNE group and normal control group.Post-hoc testing demonstrated that the C-allele carriers had a significantly decreased CBF compared to the GG homozygotes in the m PFC in the PMNE group(t =-4.279,Padjusted < 0.001).There was no significant difference between children with different genotypes in normal control group(t = 0.838,Padjusted = 0.4598).Conclusion :Among PNE children,C-allele carriers of rs747302 were associated with abnormal CBF in the thalamus and m PFC.