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No Association Between the Dopamine D 2 Receptor Taq I A1 Allele and Earlier Age of Onset of Alcohol Dependence According to Different Specified Criteria
Author(s) -
Anghelescu Ion,
Germeyer Sabine,
Müller Matthias J.,
Klawe Christoph,
Singer Peter,
Dahmen Norbert,
Wetzel Hermann,
Himmerich Hubertus,
Szegedi Armin
Publication year - 2001
Publication title -
alcoholism: clinical and experimental research
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.267
H-Index - 153
eISSN - 1530-0277
pISSN - 0145-6008
DOI - 10.1111/j.1530-0277.2001.tb02283.x
Subject(s) - cidi , alcohol dependence , taqi , allele , medicine , age of onset , gastroenterology , alcohol , binge drinking , psychology , psychiatry , polymorphism (computer science) , comorbidity , genetics , biology , alcohol consumption , national comorbidity survey , gene , disease , biochemistry
Background: The presence of the A1 allele of the dopamine D 2 receptor Taq I restriction fragment length polymorphism has been reported to be associated with an earlier age of onset of alcohol dependence as a marker for severity. Methods: We tested this hypothesis with special regard to the definition of the age of onset of alcoholism in 243 patients with alcohol dependence, according to DSM‐IV criteria assessed by the standardized interview Münchner Composite International Diagnostic Interview (M‐CIDI), consecutively admitted for detoxification. Additionally, the Addiction Severity Index (ASI) was performed. The Taq IA polymorphism was amplified by polymerase chain reaction (PCR), and the PCR product was digested by the restriction enzyme Taq I. Patients were subsequently divided into an A1 (presence of at least one A1 allele, n = 88) and an A2 group (absence of an A1 allele, n = 155). The following criteria for different definitions of age of onset were used: (1) age of onset of the first occurring symptom necessary for the diagnosis of alcohol dependence according to M‐CIDI; (2) age of onset of the last symptom of alcohol dependence according to M‐CIDI; (3) age of onset of more than 3 drinking days per week on a regular basis according to ASI; (4) age of onset of more than 3 drinking days—of more than five drinks per drinking day—or at least one binge drinking episode per week on a regular basis according to ASI. Results: The frequency of the A1 allele in our patient sample was 0.208. No statistically significant association between the A1 allele and the age of onset of alcoholism was found. The mean age of onset according to criterion 1 was 30.4 ± 10.8 years for the A1 group and 30.2 ± 10.2 years for the A2 group ( p = 0.89); for criterion 2, it was 33.3 ± 10.0 years for the A1 group and 33.9 ± 10.2 years for the A2 group ( p = 0.77); for criterion 3, it was 18.0 ± 7.5 years for the A1 group and 18.1 ± 6.1 years for the A2 group ( p = 0.92); and for criterion 4, it was 22.3 ± 9.7 years for the A1 group and 21.8 ± 8.5 years for the A2 group ( p = 0.76). Conclusions: No association was found between the A1 polymorphism and age at onset of alcohol dependence according to different specified criteria.