RESEARCH Association of ADH1B and ALDH2 gene polymorphisms with alcohol dependence: A pilot study from India Meera Vaswani,* Pushplata Prasad and Suman Kapur National Drug Dependence Treatment Centre, All India Institute of Medical Sciences, New Delhi – 110029; India *Correspondence to: Tel: þ91 11 26593244; Fax: þ91 11 26588663; E-mail: meeravaswani@yahoo.com Date received (in revised form): 7th November, 2008 Abstract Functional polymorphism in the genes encoding alcohol dehydrogenase (ADH) 1B and aldehyde dehydrogenase (ALDH) 2 are considered most important among several genetic determinants of alcohol dependence, a complex disorder. There is no report on the widely studied Arg47His and Glu487Lys polymorphisms from Indian alcohol- dependent populations. In this paper, we report, for the ﬁrst time, allelic and genotypic frequencies of Arg47His and Glu487Lys single nucleotide polymorphisms (SNPs) in North Indian alcohol-dependent subjects. A total of 174 alcohol-dependent males, recruited using DSM IV criteria (American Psychiatric Association, 1994), were genotyped using the polymerase chain reaction – restriction fragment length polymorphism method. The results obtained from genetic analysis were correlated with clinical parameters using Student’s t-test or Mann Whitney’s U test. The highlight of the study ﬁndings was the uniquely high frequency of the ALDH2*2/*2 genotype (among alcohol-dependent subjects) being a risk-conferring factor for alcohol dependence. Keywords: alcohol dependence, alcohol dehydrogenase, aldehyde dehydrogenase, genotype – phenotype correlation Introduction Alcohol dependence (AD; Mendelian Inheritance in Man, (MIM) %1037800), a chronic relapsing dis- order, is a serious health concern globally. It is charac- terised by loss of sensitivity and development of tolerance to, and withdrawal symptoms and craving for alcohol.1 In addition, AD also leads to a plethora of disabling complications, such as hepatitis, hepatic cirrhosis, chronic pancreatitis, testicular atrophy and avascular necrosis of the hip joint.2 The morbidity, mortality and high cost associated with the treatment of alcoholism and its related complications makes AD a major socio-economic burden on society. Alcohol abuse disorders result from the inter- action between an individual’s genetic and environ- mental susceptibility and repeated intake of alcohol over time. It is not possible to become alcoholic without repeatedly consuming alcohol, but only a small percentage of all drinkers become alcoholic.3 Epidemiological studies suggest that ethnicity and genetic susceptibility are crucial in the genesis of AD,4 – 10 with American Indians, Native Hawaiians, African Americans and Hispanics being highly sus- ceptible to developing AD.11 Although the prevalence of AD in the Asian population is low, a sizable number of people in India are suffering from alcohol use disorders.12 Genetic predisposition to AD, conferred by various candidate genes, differs across ethnic groups.13 This differential contribution leads to inconsistent genetic association and non-replication of associ- ation between different populations. Linkage and association studies to determine genetic factors # HENRY STEWART PUBLICATIONS 1479–7364. HUMAN GENOMICS. VOL 3. NO 3. 213–220 APRIL 2009 213