title: Potential contribution of monoamine oxidase a gene variants in ADHD and behavioral co-morbidities: scenario in eastern Indian probands.
abstract: Attention deficit hyperactivity disorder (ADHD) is the most frequently diagnosed behavioral disorder in children with a high frequency of co-morbid conditions like conduct disorder (CD) and oppositional defiant disorder (ODD). These traits are controlled by neurotransmitters like dopamine, serotonin and norepinephrine. Monoamine oxidase A (MAOA), a mitochondrial enzyme involved in the degradation of amines, has been reported to be associated with aggression, impulsivity, depression, and mood changes. We hypothesized that MAOA can have a potential role in ADHD associated CD/ODD and analyzed 24 markers in a group of Indo-Caucasoid subjects. ADHD probands and controls (N = 150 each) matched for ethnicity and gender were recruited following the Diagnostic and Statistical Manual for Mental Disorders-IV. Appropriate scales were used for measuring CD and ODD traits. Markers were genotyped by PCR-based methods and data obtained analyzed using the Cocaphase program under UNPHASED. Only eight markers were found to be polymorphic. rs6323 "G" allele showed higher frequencies in ADHD (P = 0.0023), ADHD + CD (P = 0.03) and ADHD + ODD (P = 0.01) as compared to controls. Haplotype analysis revealed statistically significant difference for three haplotypes in ADHD cases (P < 0.02). Statistically significant differences were also noticed for haplotypes in ADHD + CD and ADHD + ODD cases (P < 0.01). LD analysis showed significant variation in different groups. Multidimensionality reduction analysis showed independent as well as interactive effects of markers. Genotypes showed correlation with behavioral problems in ADHD and ADHD + CD. We interpret that MAOA gene variants may contribute to the etiology of ADHD as well as associated co-morbid CD and ODD in this ethnic group.
authors.affiliation: Manovikas Biomedical Research and Diagnostic Centre, 482, Madudah, Plot I-24, Sec.-J, E.M. Bypass, Kolkata, 700107, India.
authors.forename: A
authors.initials: A
authors.lastname: Karmakar
authors.forename: S
authors.initials: S
authors.lastname: Maitra
authors.forename: D
authors.initials: D
authors.lastname: Verma
authors.forename: B
authors.initials: B
authors.lastname: Chakraborti
authors.forename: R
authors.initials: R
authors.lastname: Goswami
authors.forename: P
authors.initials: P
authors.lastname: Ghosh
authors.forename: S
authors.initials: S
authors.lastname: Sinha
authors.forename: K P
authors.initials: KP
authors.lastname: Mohanakumar
authors.forename: R
authors.initials: R
authors.lastname: Usha
authors.forename: K
authors.initials: K
authors.lastname: Mukhopadhyay
mesh_terms: D001289:Attention Deficit Disorder with Hyperactivity / Q000201:enzymology / Q000235:genetics*; D019958:Attention Deficit and Disruptive Behavior Disorders / Q000201:enzymology / Q000235:genetics; D015897:Comorbidity; D019955:Conduct Disorder / Q000235:genetics; D005260:Female; D006239:Haplotypes; D006801:Humans; D007194:India; D008297:Male; D018598:Minisatellite Repeats; D008995:Monoamine Oxidase / Q000235:genetics*; D044465:White People / Q000235:genetics
chemical_list: D008995:Monoamine Oxidase