ADHDgene Database

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Large-scale studies

Data Summary

Published Variant
- SNP: 1391
- CNV: 398
- Others: 173
Published Gene: 359
Published Region: 128
Pathway by PBA: 8
Study: 361

Study Report

Basic Info

Reference	Das M, 200616856146
Citation	Das M., Bhowmik A. D., Sinha S., Chattopadhyay A., Chaudhuri K., Singh M. and Mukhopadhyay K. (2006) "MAOA promoter polymorphism and attention deficit hyperactivity disorder (ADHD) in indian children." Am J Med Genet B Neuropsychiatr Genet, 141B(6): 637-42.
Study Design	case-control and family-based
Study Type	Candidate-gene association study
Sample Size	73 cases and 91 healthy controls
Predominant Ethnicity	Indian
Population	India
Gender	64 males and 9 females for cases, 57 females and 34 males for controls
Age Group	Children/Adolescents : 2.4-15 years (mean age 7.66, SD=0.36 SE)

Detail Info

Summary	This is the first study on Indian ADHD cases to validate an association between transmission of MAOA promoter polymorphism and risk of ADHD. They have analyzed the MAOA promoter polymorphism in a group of ADHD probands, their parents and ethnically matched controls by UNPHASED. Their findings indicate significant difference in the frequency of 3.5 repeat allele between cases and controls and preferential transmission of the short allele (3.5 repeat) from mothers to male ADHD probands. They conclude that the short 3.5 repeat allele of the MAOA-u VNTR is probably associated with ADHD in their population and could be the reason for making boys prone to ADHD as compared to girls.
Total Sample	Seventy-three ADHD cases (64 males and 9 females) were recruited from the Out-Patient Clinic of Manovikas Kendra Rehabilitation and Research Institute for the Handicapped (Kolkata, India). The ADHD cases included in the study comprises of 67 complete parent-offspring trios and 6 mother-proband duos. The control group comprised of 148 healthy individuals (97 females and 51 males) assessed by the same psychometric evaluation procedure, out of which 91 were ethnically matched to the ADHD cases studied (57 females and 34 males).
Diagnosis Description	A child psychiatrist and clinical psychologist performed the diagnosis following DSM-IV-TR criteria. Psychological evaluation was completed through-(i) The Conners' Parents and Teachers Rating Scale [Conners et al., 1998] and (ii) Wechsler Intelligence Scale for Children [Wechsler, 1991] for the inattention-hyperactivity level and IQ status, respectively. Patients with any other neuropsychiatric disorders, pervasive developmental disorder, mental retardation including Fragile-X syndrome were excluded from the study.
Technique	Peripheral blood collected from ADHD probands, their parents and control individuals was used for genomic DNA preparation using standard protocol [Miller et al., 1998]. MAOA-u VNTR was amplified with primers: Forward-5'-ACA GCC TGA CCG TGG AGA AG-3' and Reverse-5'-GAA CGG ACG CTC CAT TCG GA-3' [Sabol et al., 1998]. Sequence analysis of the PCR products was carried out in Applied Biosystems 3130 Genetic analyzer using Big Dye v 3.1 chemistry and by Sequencing Analysis Software, v 5.2.
Analysis Method	Association analysis was carried out by UNPHASED v2.404 [Dudbridge, 2003] which allows TDTPHASE and case-control (COCAPHASE) analysis of X-linked traits and is based on likelihood ratio tests in a log-linear model using standard logistic regression. TDTPHASE treats all transmitted alleles or haplotypes as 'cases' and all non-transmitted parental alleles as 'controls'. Transmission from mother to proband was used for TDTPHASE calculation.
Result Description	Their findings indicate significant difference in the frequency of 3.5 repeat allele (P-value=0.02) between cases and controls and preferential transmission of the short allele (3.5 repeat) from mothers to male ADHD probands (P-value=0.005). They conclude that the short 3.5 repeat allele of the MAOA-u VNTR is probably associated with ADHD in their population and could be the reason for making boys prone to ADHD as compared to girls.

Other variant reported by this study (count: 1)

Variant Name	Allele Change	Risk Allele	Statistical Values	Author Comments	Result of Statistical Analysis
MAOA promoter VNTR			3.5 repeat allele LRS=5.365, df=1, P-value=0.02, OR=1 in COC...... 3.5 repeat allele LRS=5.365, df=1, P-value=0.02, OR=1 in COCAPHASE Analysis; LRS=2.29, df=1, HHRR P-value=0.13, OR=1 for full sample and 3.5 repeat allele HHRR P-value=0.005, LRS=7.97, df=1, OR=1 for male probands based on unphased data in TDTPHASE Analysis; 3.5 repeat allele ETDT P-value=0.046, LRS=3.985, df=1 for male probands based on phased data in TDTPHASE Analysis More...	the short 3.5 repeat allele of the MAOA-u VNTR is probably associated with ADHD in their population and could be the reason for making boys prone to ADHD as compared to girls	Significant

Genes reported by this study (count: 1)