Analysis of polymorphisms in the dopamine beta hydroxylase gene: association with attention deficit hyperactivity disorder in Indian children.
OBJECTIVE
To study the association of Attention Deficit Hyperactivity Disorder (ADHD) and polymorphism in the dopamine beta hydroxylase (DBH) gene in Indian ADHD cases.


METHODS
Forty one ADHD cases were diagnosed as per the DSM-IV-TR criteria and evaluated by Conners Parents and Teachers Rating Scale and Wechslers Intelligence Scale for Children.


METHODS
Genomic DNA was amplified for exon 2 *444g/a and intron 5 (Taq I) polymorphism in the DBH gene followed by restriction fragment length polymorphism (RFLP) analysis. Haplotype-based haplotype relative risk (HHRR) was analyzed to ascertain the transmission pattern of these two polymorphisms in ADHD cases. Linkage disequilibrium (LD) between the two polymorphisms was calculated using EH+ and 2LD programs.


RESULTS
In the limited number of samples analyzed, a slight increase in transmission of the 444a allele in ADHD subjects was observed for DBH 444g/a. The intron 5 (Taq I) polymorphism showed no significant association with ADHD in these cases. Strong disequilibrium was observed between DBH444g/a and intron 5 (Taq I) polymorphism.


CONCLUSIONS
This is the first molecular genetic study on ADHD in Indian subjects exploring transmission of polymorphisms in the DBH gene. Preliminary investigation shows a trend towards association between the transmission of DBH444a allele and ADHD. No association was noticed between transmission of intron 5 (Taq I) polymorphism and ADHD in the Indian subjects. Presence of strong LD may point towards co-segregation of these two polymorphisms more often than expected.
Bhaduri
Nipa
N
Manovikas Biomedical Research and Diagnostic Center, Kolkata 700 107, India.
Sinha
Swagata
S
Chattopadhyay
Anindita
A
Gangopadhyay
Prasanta Kumar
PK
Singh
Manoranjan
M
Mukhopadhyay
Kanchan Kumar
KK
D000293:Adolescent; D001289:Attention Deficit Disorder with Hyperactivity / Q000235:genetics*; D002648:Child; D002675:Child, Preschool; D004299:Dopamine beta-Hydroxylase / Q000235:genetics*; D005260:Female; D005838:Genotype; D006239:Haplotypes; D006801:Humans; D007194:India; D015810:Linkage Disequilibrium; D008297:Male; D011110:Polymorphism, Genetic; D012150:Polymorphism, Restriction Fragment Length
D004299:Dopamine beta-Hydroxylase