Dopamine D4 Receptor Gene Polymorphism in a Sample of Egyptian Children With Attention-Deficit Hyperactivity Disorder (ADHD).
This study aimed to detect DRD4 receptor gene polymorphisms in attention-deficit hyperactivity disorder (ADHD) children and to correlate their phenotype-genotype. Fifty children with ADHD were diagnosed by Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition, criteria and were subjected to Conners Parent Rating Scale. All cases and controls were subjected to history taking, physical examination, IQ assessment, and dopamine receptor D4 (DRD4) exon 3 genotyping. The 7-repeat allele was present only in controls, whereas 2-repeat allele was present in the ADHD children (heterozygous 2-repeat allele in 16% and homozygous in 26% of cases). Eight percent of cases had homozygous 4-repeat allele vs 28% of controls, whereas 10% of cases had heterozygous 4-repeat allele vs 6% of controls, with its predominance in controls. The 2-repeat and 4-repeat alleles have been associated with more inattention, hyperactivity, and impulsivity phenotypes. In conclusion, children with ADHD had a significant presence of the 2-repeat allele and absence of the 7-repeat allele.
1 Pediatrics Department, Faculty of Medicine, Ain Shams University, Cairo, Egypt.
Farida
F
ElBaz Mohamed
1 Pediatrics Department, Faculty of Medicine, Ain Shams University, Cairo, Egypt.
Tarek Mostafa
TM
Kamal
1 Pediatrics Department, Faculty of Medicine, Ain Shams University, Cairo, Egypt.
Sally Soliman
SS
Zahra
1 Pediatrics Department, Faculty of Medicine, Ain Shams University, Cairo, Egypt.
Mona Abdel Hakiem
MA
Khfagy
1 Pediatrics Department, Faculty of Medicine, Ain Shams University, Cairo, Egypt.
Azza Mohamed
AM
Youssef
D000293:Adolescent; D001289:Attention Deficit Disorder with Hyperactivity / Q000175:diagnosis / Q000235:genetics* / Q000523:psychology; D002648:Child; D003241:Consanguinity; D039721:Diagnostic and Statistical Manual of Mental Disorders; D004534:Egypt; D005091:Exons; D005260:Female; D056726:Genetic Association Studies; D060005:Genotyping Techniques; D006720:Homozygote; D006801:Humans; D007361:Intelligence Tests; D019656:Loss of Heterozygosity; D008297:Male; D011110:Polymorphism, Genetic; D050638:Receptors, Dopamine D4 / Q000235:genetics*
C493599:DRD4 protein, human; D050638:Receptors, Dopamine D4
D4 receptor gene; attention-deficit hyperactivity disorder (ADHD); genotype; phenotype; polymorphism