Study Report

Basic Info
Reference |
Zoroglu SS, 200212097805
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Citation |
Zoroglu S. S., Erdal M. E., Alasehirli B., Erdal N., Sivasli E., Tutkun H., Savas H. A. and Herken H. (2002) "Significance of serotonin transporter gene 5-HTTLPR and variable number of tandem repeat polymorphism in attention deficit hyperactivity disorder." Neuropsychobiology, 45(4): 176-81.
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Study Design |
case-control |
Study Type |
Candidate-gene association study |
Sample Size |
71 patients and 128 controls |
Predominant Ethnicity |
Turkish |
Population |
Turkey |
Gender |
55 male and 16 female patients, 89 male and 39 female controls |
Age Group |
Children/Adolescents
:
case: 6-17 years (mean= 9.9, SD=4.1); control: 6-17 years (mean=10.1, SD=4.6)
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Detail Info
Summary |
The purpose of this study was to evaluate the relationship between attention deficit hyperactivity disorder (ADHD) and polymorphism of the two regions of the 5-HTT gene [variable number of tandem repeats (VNTR) and 5- HTTLRR] in a sample of Turkish children. Using the PCR technique, these polymorphisms were assessed in 71 patients with ADHD and 128 healthy controls. The 5- HTTLPR S/S genotype was significantly lower in the patients than in the controls. Homozygous and heterozygous L variant predominated in the ADHD group. But the VNTR STin2.12/12 genotype was significantly less found in the patients than in the controls. There was no significant difference between the frequency of the short (S), long, 10, and 12 alleles of both groups. The lack of an S/S variant of 5-HTTLPR polymorphism of the STin2.12/12 variant of VNTR polymorphism appears to be associated with an increased risk of ADHD. |
Total Sample |
Seventy-one patients with ADHD and 128 healthy volunteers were included in the study. There were 55 male and 16 female patients with ADHD with their ages ranging from 6 to 17 years, and 89 male and 39 female controls with their ages ranging from 6 to 17 years. |
Sample Collection |
ADHD patients were recruited from the Child and Adolescent Psychiatry Clinic of University Hospital of Gaziantep, Turkey. |
Diagnosis Description |
The diagnosis of ADHD was made on the basis of DSM-IV criteria. The clinical assessment included the following parts: (1) The Child Behavior Checklist (CBCL); (2) The Conners Parent Rating Scale; (3) The Conners Teacher Rating Scale; (4) The ADHD Rating Scale-IV; (5) The Schedule for Affective Disorders and Schizophrenia for school-age children, lifetime version |
Technique |
Using the PCR technique, polymorphism of the two regions (VNTR and 5-HTTLPR) of the 5-HTT gene was analyzed in the DNAs obtained from leUnited Kingdomocytes of the patients and healthy controls. |
Analysis Method |
For the statistical analysis, SPSS (10.0 version) for Windows computing program was used. For mean scores of clinical rating scales and age, comparisons between the ADHD and control group were performed by using Student t tests. Categorical variables were compared by Pearson's X2 or Fisher's exact test. Two-tailed significance values were used. |
Result Description |
The 5-HTTLPR S/S genotype was significantly lower in the patients than in the controls (p=0.018). Homozygous and heterozygous L variant predominated in the ADHD group. But the VNTR STin2.12/12 genotype was significantly less found in the patients than in the controls (p=0.001). There was no significant difference between the frequency of the short (S), long, 10, and 12 alleles of both groups. The lack of an S/S variant of 5-HTTLPR polymorphism of the STin2.12/12 variant of VNTR polymorphism appears to be associated with an increased risk of ADHD. |

Other variant reported by this study (count: 2)
Variant Name |
Allele Change |
Risk Allele |
Statistical Values |
Author Comments |
Result of Statistical Analysis |
5HTTLPR |
short/long |
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Fisher¡¯s exact test, allelic P-value=0.289; Pearson P-value......
Fisher¡¯s exact test, allelic P-value=0.289; Pearson P-value=0.018, X2=8.003, d.f.=2 of S/S genotype
More...
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S and L alleles of 5-HTTLPR were similar between the controls and patients; the 5-HTTLPR S/S genotype was represented significantly less in the patients than in the controls |
Significant
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SLC6A4 intron2 VNTR |
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Fisher¡¯s exact test, allelic P-value=0.288; Pearson P-value......
Fisher¡¯s exact test, allelic P-value=0.288; Pearson P-value=0.001, X2=13.27, d.f.=2 of STin2.12/12 genotype
More...
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there was no significant difference between the frequencies of the VNTR STin2.10 and STin2.12 alleles; the VNTR STin2.12/12 genotype was significantly less in the patients than the controls |
Significant
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Genes reported by this study (count: 1)
Gene |
Statistical Values/Author Comments |
Result of Statistical Analysis |
SLC6A4 |
The lack of an S/S variant of 5-HTTLPR polymorphism of the S......
The lack of an S/S variant of 5-HTTLPR polymorphism of the STin2.12/12 variant of VNTR polymorphism appears to be associated with an increased risk of ADHD.
More...
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Significant
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