Genetic Polymorphism of the CCK Gene in Patients With Alcohol Withdrawal Symptoms

Background: Cholecystokinin (CCK) is considered to play an important role in the central nervous system via its interaction with other neurotransmitters such as dopamine, serotonin, gamma-aminobutyric acid, substance P, and enkephalins. We investigated the relationship between the C to T substitution in the Spl binding cis-element of the CCK gene promoter region (at position −45 numbered from initiation codon) and alcohol withdrawal symptoms. Methods: We examined 214 Japanese men with alcoholism (93 with delirium tremens, 49 with hallucination, 38 with seizure, and 93 with none of these symptoms) and 98 age-matched Japanese male controls by using a polymerase chain reaction-based single strand conformational polymorphism analysis. Results: Patients who displayed hallucination were significantly more likely to possess the C allele than control subjects (X² = 8.17, p = 0.017, Bonferroni correction: p = 0.064). In addition, we investigated the influence of CCK gene polymorphism on alcohol consumption among the control subjects but found no significant relationship. Conclusions: Our data suggested that the C allele at −45 locus of the CCK gene was higher in patients with hallucination than the control group at a rate that was not quite significant after Bonferroni correction for multiple testing.