Association Study of a Functional MAOA-uVNTR Gene Polymorphism and Cognitive Function in Healthy Females

Abstract

Monoamine oxidase A (MAOA) is a mitochondrial enzyme involved in the degradation of dopamine, serotonin and norepinephrine and these neurotransmitters are hypothesized to be involved in the cognitive function of humans. This study of a cohort of 191 healthy young Chinese females attempts to utilize the intelligence quotient (IQ), Wisconsin Card Sorting Test (WCST) and P300 event-related potentials as cognitive assessments for testing the relationship between the polymorphism with a variable number of tandem repeats (VNTR) in the upstream regulatory region (MAOA-uVNTR) and cognition. The results demonstrate that subjects bearing the 4/4-repeat genotype have a significantly higher full IQ than subjects bearing the 3/3-repeat genotype. However, there is no significant association between this MAOA-uVNTR polymorphism and the WCST and P300. Our study shows that the MAOA-uVNTR genetic polymorphism plays a role in the IQ; however, this may be a chance finding as the result was negative after using the Bonferroni adjustment. Therefore, we suggest that our study should be replicated and that the testing method, sex, disease and ethnicity should also be considered in future studies.

Gene–Gene Interaction Between COMT and MAOA Potentially Predicts the Intelligence of Attention-Deficit Hyperactivity Disorder Boys in China

“…ADHD boys carrying the MAOA-3R genotype had higher FSIQ, VIQ, and PIQ scores than subjects with the 4R genotype. This finding was inconsistent with the studies of Tsai et al (2003) and Yu et al (2005) in healthy females of Han Chinese origin, which showed that met/met homozygotes had no association with cognitive tasks including IQs. In contrast to our findings, Yu et al (2005) found that the FSIQ was significantly higher for females bearing the MAOA-uVNTR 4/4-repeat genotype in comparison to the 3/3-repeat genotype.…”

Performance in the Wisconsin Card Sorting Test and the C957T Polymorphism of the <i>DRD2</i> Gene in Healthy Volunteers

“…A structured clinical interview was then conducted by psychiatrists using the Mini-International Neuropsychiatric Interview [27] in order to exclude subjects with psychiatric disorders. These methods are similar to those employed in other studies with healthy subjects [28] . Our final sample included 83 individuals (28 males and 55 females), whose mean age was 25.2 years (SD: 1.7).…”

“…Several studies have found an association between cognitive functioning and different genetic polymorphisms of the dopaminergic system, such as the COMT gene [21][22][23][24] , the MAO-A gene [28] , or the DRD1 gene [20] . However, we have no knowledge of previous studies investigating the relationship between the C957T DRD2 SNP and executive functions in healthy subjects.…”

MAOA Influences the Trajectory of Attentional Development

“…For example, APOE , SLC5A7 , and CHRNA4 are all associated with the neurotransmitter acetylcholine, which has been associated with cognitive development (McKinnon and Nathanson, 1995) and with visuospatial attention, ADHD, and distractibility (Manuck et al, 2000; Manor, 2002; Störmer et al, 2012; Markant et al, 2014). Likewise, BDNF , HTR4 , and Monoamine oxidase A ( MAOA ) are associated with serotonin, although MAOA and BDNF also influence dopamine availability (Yu et al, 2005; Razgado-Hernandez et al, 2015; Voigt et al, 2015; Parikh et al, 2016). Serotonin has been associated with brain and attentional development (Binder and Scharfman, 2004; Shim et al, 2008; Faraone and Mick, 2010) and with ADHD (Poirier, 1996; Greenwood et al, 2000; Fisher et al, 2002; Parasuraman et al, 2002; Walitza et al, 2005; Winterer et al, 2007).…”