▁meg alin ▁protein . ▁However , ▁it ▁is ▁unclear ▁how ▁these ▁ab normal ities ▁result ▁in ▁the ▁specific ▁signs ▁and ▁sympt oms ▁of ▁the ▁dis order . ▁ ▁A ▁condition ▁previously ▁class ified ▁as ▁a ▁separate ▁dis order ▁called ▁fa cio - oc ulo - ac oust ico - ren al ▁( FO AR ) ▁synd rome ▁has ▁also ▁been ▁found ▁to ▁be ▁caused ▁by ▁L R P 2 ▁mut ations . ▁FO AR ▁synd rome ▁is ▁now ▁considered ▁to ▁be ▁the ▁same ▁dis order ▁as ▁Don na i – B arrow ▁synd rome . ▁ ▁In her ited ▁mut ation ▁This ▁condition ▁is ▁inherited ▁in ▁an ▁aut os om al ▁re cess ive ▁pattern , ▁which ▁means ▁both ▁copies ▁of ▁the ▁gene ▁in ▁each ▁cell ▁have ▁mut ations . ▁In ▁almost ▁all ▁cases , ▁the ▁parents ▁of ▁an ▁individual ▁with ▁an ▁aut os om al ▁re cess ive ▁condition ▁each ▁carry ▁one ▁copy ▁of ▁the ▁mut ated ▁gene ▁but ▁typically ▁do ▁not ▁show ▁signs ▁and ▁sympt oms ▁of ▁the ▁condition . ▁ ▁One ▁individual ▁with ▁Don na i – B arrow ▁synd rome ▁was ▁found ▁to ▁have ▁inherited ▁both ▁copies ▁of ▁the ▁mut ated ▁gene ▁from ▁his ▁father ▁as ▁a ▁result ▁of ▁a ▁gen etic ▁change ▁called ▁un ip ar ental ▁dis omy ▁( UP D ). ▁UP D ▁occurs ▁when ▁a ▁person ▁receives ▁two ▁copies ▁of ▁a ▁chrom os ome , ▁or ▁part ▁of ▁a ▁chrom os ome , ▁from ▁one ▁parent ▁and ▁no ▁copies ▁from ▁the ▁other ▁parent . ▁UP