Evidence of Genetic Predisposition to Alcoholic Cirrhosis and Psychosis: Twin Concordances for Alcoholism and Its Biological End Points by Zygosity among Male Veterans

Publisher Website
Google Scholar
Abstract
Medical histories of the 15,924 male twin pairs in the National Academy of Sciences-National Research Council Twin Registry were examined to determine, within pairs, concordances for alcoholism and its medical end points. Prevalences per 1000 among individual twin subjects were 29.6 for alcoholism, 4.1 for alcoholic psychosis, 14.2 for liver cirrhosis and 2.1 for pancreatitis. Prevalences were similar for monozygotic (MZ) and dizygotic (DZ) twins. Prevalences in percent among co-twins of diagnosed subjects, that is case-wise twin concordance rates, were, respectively, by diagnosis; alcoholism: 26.3 (MZ), 11.9 (DZ); alcoholic psychosis: 21.1 (MZ), 6.0 (DZ); and liver cirrhosis: 14.6 (MZ), 5.4 (DZ). No twin pairs concordant for pancreatitis were found. The greater concordance for alocholic psychosis and for liver cirrhosis among MZ than DZ twins could not be explained by the difference in alcoholism concordance between them. The difference in concordance between MZ and DZ twins persisted when, in addition, it was assumed that only 1/2 of the actually occurring cases of alcoholism and of each of the end points were ascertained. These results provide evidence in favor of genetic predispositon to organ-specific complications of alcoholism and should serve to stimulate searches for the underlying biochemical mechanisms.