Association of neuropeptide Y polymorphism with the occurrence of type I and type 2 alcoholism

Background: The susceptibility to alcoholism can be explained partially by genetic factors. Neuropeptide Y (NPY) has emerged as one potential factor c ontributing the development of alcoholism. A recent study indicated that th e NPY gene variant producing a leucine-to-proline substitution (T to C at p osition 1128) was associated with 34% higher average alcohol consumption. Methods: The subjects consisted of 122 alcoholics classified as type 1 and type 2 subtypes by psychiatric evaluation. A random sample of 59 social dri nkers was used as a control group to compare the distribution of NPY genoty pes with those of alcoholics. Results: In a logistical regression model, there was a significantly lower frequency of the leucine(7)/proline(7) heterozygotes among well characteriz ed type 2 alcoholics, compared with the controls (10.8 vs. 24.1%, p = 0.028 ). Conclusions: We speculate that the genetic polymorphism producing the proli ne(7) substitution of NPY might not predispose to alcoholism, but indeed re tard the transition to alcoholism.