Neuropeptide Y receptor genes are associated with alcohol dependence, alcohol withdrawal phenotypes, and cocaine dependence.
BACKGROUND
Several lines of evidence in both human and animal studies suggest that variation in neuropeptide Y (NPY) or its receptor genes (NPY1R, NPY2R and NPY5R) is associated with alcohol dependence as well as alcohol withdrawal symptoms. Additional studies suggest that cocaine may affect NPY expression.


METHODS
A total of 39 single nucleotide polymorphisms (SNPs) were genotyped across NPY and its 3 receptor genes in a sample of 1,923 subjects from 219 multiplex alcoholic families of European American descent recruited as part of the Collaborative Studies on the Genetics of Alcoholism (COGA) study. Family-based association analysis was performed to test the primary hypothesis that variation in these genes is associated with alcohol dependence. Secondary analyses evaluated whether there was an association of these SNPs with symptoms of alcohol withdrawal, cocaine dependence, or comorbid alcohol and cocaine dependence.


RESULTS
Although variations in NPY itself were not associated with these phenotypes, variations in 2 NPY-receptor genes were. SNPs in NPY2R provided significant evidence of association with alcohol dependence, alcohol withdrawal symptoms, comorbid alcohol and cocaine dependence, and cocaine dependence (all p < 0.03). Haplotype analyses strengthened the evidence for these phenotypes (global 0.0004 < p < 0.005). SNPs in NPY5R demonstrated significant association with alcohol withdrawal characterized by seizures (p < 0.05).


CONCLUSIONS
These results indicate that sequence variations in NPY receptor genes are associated with alcohol dependence, particularly a severe subtype of alcohol dependence characterized by withdrawal symptoms, comorbid alcohol and cocaine dependence, and cocaine dependence.
Wetherill
Leah
L
Indiana University School of Medicine, Indianapolis, Indiana 46202, USA.
Schuckit
Marc A
MA
Hesselbrock
Victor
V
Xuei
Xiaoling
X
Liang
Tiebing
T
Dick
Danielle M
DM
Kramer
John
J
Nurnberger
John I
JI
Tischfield
Jay A
JA
Porjesz
Bernice
B
Edenberg
Howard J
HJ
Foroud
Tatiana
T
D000437:Alcoholism / Q000150:complications / Q000235:genetics* / Q000503:physiopathology; D019970:Cocaine-Related Disorders / Q000150:complications / Q000235:genetics* / Q000503:physiopathology; D005787:Gene Frequency / Q000235:genetics; D014644:Genetic Variation / Q000235:genetics; D006801:Humans; D010641:Phenotype; D020641:Polymorphism, Single Nucleotide / Q000235:genetics; D017476:Receptors, Neuropeptide Y / Q000235:genetics*; D013375:Substance Withdrawal Syndrome / Q000150:complications / Q000235:genetics* / Q000503:physiopathology
D017476:Receptors, Neuropeptide Y