The ANKK1 gene is closely linked to dopamine receptor D2 (DRD2) on chromosome band 11q23.1. The A1 allele of the Taq1A polymorphism (rs1800497T), is located ≈10kb downstream of the dopamine receptor DRD2 gene. Dopamine (DA) is a neurotransmitter in the brain, which controls feelings of wellbeing. This sensation results from the interaction of dopamine and other neurotransmitters such as serotonin, the opioids, and other brain chemicals. Dopamine increases the motivation for food cravings and appetite mediation.
The Reward Deficiency Syndrome (RDS) involves the pleasures or reward mechanisms that rely on dopamine. The result of this deficiency is based on the genetic makeup; this helps explain how certain simple genetic anomalies can give rise to complex aberrant behaviours as the ones mentioned previously. The A1 allelic prevalence has been reported to be significantly higher in obese individuals than in lean subjects, moreover, individuals with increased body mass index (BMI) (BMI >30 kg/m²) have fewer DRD2 dopamine receptors. Investigators have also suggested that hormonal mechanism may underline a gender difference in the ability to suppress hunger in relation to this SNP, which may contribute to the greater incidence of obesity in women compared to men. However, authors have pointed out that A1 carriers have difficulty in learning from negative feedback in a reinforcement-learning task and are less efficient at learning to avoid actions that have negative consequences.
^Lucht M, Rosskopf D (July 2008). "Comment on "Genetically determined differences in learning from errors"". Science. 321 (5886): 200; author reply 200. doi:10.1126/science.1155372. PMID18621654.
^Neville MJ, Johnstone EC, Walton RT (June 2004). "Identification and characterization of ANKK1: a novel kinase gene closely linked to DRD2 on chromosome band 11q23.1". Hum. Mutat. 23 (6): 540–5. doi:10.1002/humu.20039. PMID15146457.
^Laakso A, Pohjalainen T, Bergman J, Kajander J, Haaparanta M, Solin O, Syvälahti E, Hietala J (June 2005). "The A1 allele of the human D2 dopamine receptor gene is associated with increased activity of striatal L-amino acid decarboxylase in healthy subjects". Pharmacogenet. Genomics. 15 (6): 387–91. doi:10.1097/01213011-200506000-00003. PMID15900211.
^Lawford B, Young R, Noble EP, Crawford D, Rowell J, Shadforth S, Ritchie T, Zhang X, Cooksley GE (January 1999). "The DRD2A₁allele: a behavioural genetic risk factor in hepatitis C infection of persistent drug abusers". Addict Biol. 4 (1): 61–6. doi:10.1080/13556219971858. PMID20575771.
^Lu RB, Lee JF, Huang SY, Lee SY, Chang YH, Kuo PH, Chen SL, Chen SH, Chu CH, Lin WW, Wu PL, Ko HC (November 2010). "Interaction between ALDH2*1*1 and DRD2/ANKK1 TaqI A1A1 genes may be associated with antisocial personality disorder not co-morbid with alcoholism". Addict Biol. 17: 865–874. doi:10.1111/j.1369-1600.2010.00268.x. PMID21070510.
^Ponce G, Hoenicka J, Jiménez-Arriero MA, Rodríguez-Jiménez R, Aragüés M, Martín-Suñé N, Huertas E, Palomo T (August 2008). "DRD2 and ANKK1 genotype in alcohol-dependent patients with psychopathic traits: association and interaction study". Br J Psychiatry. 193 (2): 121–5. doi:10.1192/bjp.bp.107.041582. PMID18669994.
^Blum K, Braverman ER, Wu S, Cull JG, Chen TJ, Gill J, Wood R, Eisenberg A, Sherman M, Davis KR, Matthews D, Fischer L, Schnautz N, Walsh W, Pontius AA, Zedar M, Kaats G, Comings DE (May 1997). "Association of polymorphisms of dopamine D2 receptor (DRD2), and dopamine transporter (DAT1) genes with schizoid/avoidant behaviors (SAB)". Mol. Psychiatry. 2 (3): 239–46. doi:10.1038/sj.mp.4000261. PMID9152988.
^"rs1800497". Reference SNP(refSNP) Cluster Report. United States National Center for Biotechnology Information.
^Neville MJ, Johnstone EC, Walton RT (22 April 2004). "Identification and characterization of ANKK1: A novel kinase gene closely linked to DRD2 on chromosome band 11q23.1". Human Mutation. 23 (6): 540–545. doi:10.1002/humu.20039. PMID15146457.