In 1979-81 we studied 206 twin pairs in Sydney to estimate the importance of genetic factors in alcohol metabolism and psychomotor sensitivity. Sib-pair linkage analysis suggests that variants in the class I ADH region on chromosome 4 account for at least half the genetic variation in ethanol metabolism. Most interesting is that the combined ADH2/3 genotype appears to account for about 6 % of variance in alcohol consumption and dependence in men.
(N.G. Martin, A.J. Birley and J.B. Whitfield, Royal Prince Alfred Hospital, Sydney)