ity ▁group ▁to ▁another ▁and ▁thereby ▁alter , ▁perhaps ▁dram atically , ▁the ▁phen ot ype ▁produced ▁by ▁the ▁gl u 4 8 7 ly s ▁alle le : ▁the ▁alco hol - indu ce ▁re actions ▁of ▁Japanese ▁with ▁the ▁gl u 4 8 7 ly s ▁alle le ▁may ▁not ▁be ▁good ▁predict ors ▁of ▁those ▁occurr ing ▁in ▁other ▁national ity ▁groups . ▁" So cial ▁factors ", ▁despite ▁claims ▁made ▁by ▁social ▁construction ists , ▁have ▁no ▁impact ▁on ▁a ▁gen etic ▁al de hy de ▁de h ydro gen ase ▁def ic iency . ▁ ▁In ▁non - A si ans ▁The ▁pre val ence ▁of ▁eth an ol - indu ced ▁all erg ic ▁sympt oms ▁in ▁non - As ian ▁gen ot ypes ▁commonly ▁ranges ▁above ▁ 5 % ▁even ▁though ▁many ▁of ▁these ▁non - As ian ▁populations ▁have ▁no ▁or ▁very ▁low ▁levels ▁of ▁individuals ▁bearing ▁the ▁gl u 4 8 7 ly s ▁alle le . ▁ ▁These ▁" eth an ol ▁react ors " ▁may ▁have ▁other ▁gene - based ▁ab normal ities ▁that ▁cause ▁the ▁accum ulation ▁of ▁ac etal de hy de ▁following ▁the ▁ing estion ▁of ▁eth an ol ▁or ▁eth an ol - cont aining ▁be ver ages . ▁ ▁For ▁example , ▁the ▁survey ed ▁inc idence ▁of ▁self - report ed ▁eth an ol - indu ced ▁fl ushing ▁re actions ▁in ▁Sc and in av ians ▁living ▁in ▁C open hagen ▁as ▁well ▁as ▁Austral