The Dopamine Receptor D5 May Influence Age of Onset: An Exploratory Study on Indo-Caucasoid ADHD Subjects

• Published in: Journal of child neurology 2016-09, Vol.31 (10), p.1250-1256
• Main Authors: Maitra, Subhamita, Sarkar, Kanyakumarika, Sinha, Swagata, Mukhopadhyay, Kanchan
• Format: Article
• Language: English
• Subjects: Age of Onset; Attention Deficit Disorder with Hyperactivity - ethnology; Attention Deficit Disorder with Hyperactivity - genetics; Case-Control Studies; Child; Endophenotypes; European Continental Ancestry Group - genetics; Exons; Female; Genetic Predisposition to Disease; Haplotypes; Humans; India; Male; Polymorphism, Single Nucleotide; Receptors, Dopamine D5 - genetics; Severity of Illness Index
• ISSN: 0883-0738; 1708-8283
• DOI: 10.1177/0883073816652233

The objective was to investigate contribution of the dopamine receptor 5 (DRD5) gene variants in the symptoms of attention-deficit/hyperactivity disorder (ADHD) probands since brain regions identified to be affected in these group of patients have higher expression of the DRD5 receptor. Out of 22 exonic variants, 19 were monomorphic in the Indo-Caucasoid individuals. rs6283 “C” and rs113828117 “A” exhibited significant higher occurrence in families with ADHD probands. Several haplotypes showed biased occurrence in the probands. Early and late onset groups exhibited significantly different genotypic frequencies. A new G>A substitution was observed in the control samples only. The late onset group exhibited higher scores for hyperactivity as compared to the early onset group. The authors infer that the age of onset of ADHD may at least partially be affected by DRD5 variants warranting further investigation on the role of DRD5 in the disease etiology.