Family-based association study of the serotonin transporter promoter region polymorphism (5-HTTLPR) in attention deficit hyperactivity disorder.
Low serotonin activity has been associated in both animal and human studies with measures of impulsivity, aggression, and disinhibited behaviors. Recently, a common 44-bp deletion in the promoter region of the serotonin transporter (5-HTTLPR) that results in reduced transcription and lower transporter protein levels was described. Toward unraveling a possible role of the 5-HTTLPR polymorphism in childhood disruptive behaviors, we examined this gene in attention deficit hyperactivity disorder (ADHD), a heterogeneous childhood disorder in which three phenotypes are recognized by DSM IV criteria: inattentive (type I), hyperactive-impulsive (type II), and combined type (type III). By using the haplotype relative risk design, a group of 98 triads (both parents and proband child) were tested for a possible association between 5-HTTLPR and ADHD. A significant decrease in the short/short 5-HTTLPR genotype was observed in the ADHD type III combined group (10.29% vs. 30.88%) compared with the HRR-derived control group (likelihood ratio = 9.62, P = 0.008, n = 68 triads). Similar results were observed when allele frequencies were compared (likelihood ratio = 3.81, P = 0.05, n = 136 alleles). These first findings should be interpreted cautiously until replicated in independently recruited clinical samples.
Manor
I
I
Geha Mental Health Center, Petak Tikvah, Israel.
Eisenberg
J
J
Tyano
S
S
Sever
Y
Y
Cohen
H
H
Ebstein
R P
RP
Kotler
M
M
D000293:Adolescent; D001289:Attention Deficit Disorder with Hyperactivity / Q000235:genetics*; D002352:Carrier Proteins / Q000235:genetics*; D016022:Case-Control Studies; D002648:Child; D002675:Child, Preschool; D005190:Family; D005260:Female; D017353:Gene Deletion; D005787:Gene Frequency; D005838:Genotype; D006239:Haplotypes; D006801:Humans; D008297:Male; D008562:Membrane Glycoproteins / Q000235:genetics*; D026901:Membrane Transport Proteins; D009419:Nerve Tissue Proteins; D016133:Polymerase Chain Reaction; D011110:Polymorphism, Genetic / Q000235:genetics*; D011401:Promoter Regions, Genetic / Q000235:genetics*; D012306:Risk; D012701:Serotonin / Q000235:genetics*; D050486:Serotonin Plasma Membrane Transport Proteins
D002352:Carrier Proteins; D008562:Membrane Glycoproteins; D026901:Membrane Transport Proteins; D009419:Nerve Tissue Proteins; C493230:SLC6A4 protein, human; D050486:Serotonin Plasma Membrane Transport Proteins; D012701:Serotonin