ic ▁be verage ▁but ▁not ▁the ▁same ▁be verage ▁without ▁eth an ol ▁el ic its ▁re actions . ▁Either ▁result ▁would ▁favor ▁an ▁ac etal de hy de - indu ced ▁gen etic ▁basis ▁for ▁the ▁reaction . ▁▁▁▁▁▁▁▁▁ ▁Di agn osis ▁of ▁alco hol ▁sens itivity ▁due ▁to ▁the ▁accum ulation ▁of ▁ac etal de hy de ▁in ▁individuals ▁bearing ▁the ▁gl u 4 8 7 ly s ▁A LD H 2 ▁alle le ▁can ▁be ▁made ▁by ▁meas uring ▁the ▁diameter ▁of ▁the ▁er yth ema ▁( i . e . ▁red ) ▁area ▁developing ▁under ▁a ▁ 1 5 ▁millimeter ▁skin ▁patch ▁pl aster ▁so aked ▁in ▁ 7 0 % ▁eth an ol ▁and ▁applied ▁for ▁ 4 8 ▁hours ▁( eth an ol ▁patch ▁test ); ▁er yth ema ▁of ▁ 1 5 ▁mill im eters ▁is ▁considered ▁positive ▁with ▁a ▁false ▁positive ▁ratio ▁([ 1 0 0 ▁x ▁{ number ▁of ▁individuals ▁with ▁a ▁positive ▁patch ▁test }] /{ number ▁of ▁individuals ▁with ▁a ▁normal ▁A LD H 2 ▁gen ot ype }) ▁of ▁ 5 . 9 % ▁and ▁a ▁false ▁negative ▁ratio ▁([ 1 0 0 ▁x ▁{ number ▁of ▁individuals ▁with ▁a ▁negative ▁patch ▁test }] /{ number ▁of ▁individuals ▁with ▁a ▁gl u 4 8 7 ly s ▁A LD H 2 ▁alle le }) ▁of ▁ 0 %. ▁ ▁To ▁resolve ▁ambigu ities ▁in ▁or ▁replace ▁the ▁eth an ol ▁patch ▁test ▁for ▁other ▁reasons , ▁a ▁polym er ase ▁chain