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	Simsek M, 200515993876
Citation	Simsek M., Al-Sharbati M., Al-Adawi S., Ganguly S. S. and Lawatia K. (2005) "Association of the risk allele of dopamine transporter gene (DAT1*10) in Omani male children with attention-deficit hyperactivity disorder." Clin Biochem, 38(8): 739-42.
Study Design	case-control
Study Type	Candidate-gene association study
Sample Size	110 controls and 92 cases
Predominant Ethnicity	Omani
Population	Oman
Age Group	Children/Adolescents

Detail Info

Summary	The objective is to determine the frequency of the VNTR alleles in the human dopamine transporter gene (DAT1) in the Omani population and to investigate association of the VNTR alleles with attention-deficit hyperactivity disorder (ADHD). 92 Omani children with ADHD and 110 healthy Omani subjects were genotyped for the DAT1-VNTR polymorphism in a case-control study using two independent PCR tests (one developed in our laboratory) followed by agarose gel electrophoresis. They determined the DAT1-VNTR alleles in 202 Omani subjects. There were two common alleles (DAT19 and 10) and five rare ones. The DAT110 allele distribution was essentially the same both in the control (60.9%) and the patient group (64.6%). There was, however, a relatively higher occurrence of the DAT110 allele in ADHD males (69.4%) than females (55%), but this gender difference was not present in the control group (males 60%, females 62%).
Total Sample	This study included 110 healthy Omani blood donors at Sultan Qaboos University Hospital (SQUH) as control subjects and 92 Omani children attending the child and adolescent psychiatry clinic at SQUH as ADHD cases.
Sample Collection	This study included 110 healthy Omani blood donors at Sultan Qaboos University Hospital (SQUH) as control subjects and 92 Omani children attending the child and adolescent psychiatry clinic at SQUH as ADHD cases.
Diagnosis Description	The diagnosis of ADHD in children was according to the DSM-4 criteria (Diagnostic and Statistical Manual of Mental Disorders), and related subjects such as brothers or sisters were excluded. With the aid of an attending child psychiatrist, the parents of each case filled a questionnaire including all the questions related to ADHD syndromes and approved a consent form for providing blood in this study.
Technique	5 mL of EDTA blood was collected from each subject, and genomic DNA was extracted from frozen blood using a standard salting out procedure. The VNTR region of the DAT1 gene was amplified from the genomic DNA using two independent polymerase chain reactions (PCR) to minimize possible genotyping errors. Primers used in one PCR system were as described by Vandenbergh et al., and in the second PCR, they used a new set of primers: DAT1-D3 (5'GCT CAG GCTACT GCC ACT CAG GCA-3') and DAT1- D4 (5'-GAT GTG GCA CGC ACC TGA GAG AAA-3'). The PCR conditions were as described before. The PCR products were separated on a 2% agarose gel and stained with ethidium bromide.
Analysis Method	not mentioned in the original publication
Result Description	The DAT110 allele distribution was essentially the same both in the control (60.9%) and the patient group (64.6%). There was, however, a relatively higher occurrence of the DAT110 allele in ADHD males (69.4%) than females (55%), but this gender difference was not present in the control group (males 60%, females 62%).

Other variant reported by this study (count: 1)

Variant Name	Allele Change	Risk Allele	Statistical Values	Author Comments	Result of Statistical Analysis
SLC6A3 3'-UTR VNTR		10R	observed genotype frequencies, P-value>0.05; risk allele (10...... observed genotype frequencies, P-value>0.05; risk allele (10R) distribution, P-value=0.06, X²(df=1)=3.65 More...	lack of a significant difference between cases and controls	Non-significant

Genes reported by this study (count: 1)