▁( AL AD , ▁also ▁called ▁por ph obil in ogen ▁synth ase ), ▁which ▁is ▁required ▁for ▁normal ▁h eme ▁synth esis . ▁ ▁Gen et ics ▁▁ ▁A LA ▁de h yd rat ase ▁def ic iency ▁is ▁inherited ▁in ▁an ▁aut os om al ▁re cess ive ▁manner . ▁This ▁means ▁a ▁defect ive ▁gene ▁responsible ▁for ▁the ▁dis order ▁is ▁located ▁on ▁an ▁aut os ome , ▁and ▁two ▁copies ▁of ▁the ▁defect ive ▁gene ▁( one ▁inherited ▁from ▁each ▁parent ) ▁are ▁required ▁in ▁order ▁to ▁be ▁born ▁with ▁the ▁dis order . ▁The ▁parents ▁of ▁an ▁individual ▁with ▁an ▁aut os om al ▁re cess ive ▁dis order ▁both ▁carry ▁one ▁copy ▁of ▁the ▁defect ive ▁gene , ▁but ▁usually ▁do ▁not ▁experience ▁any ▁signs ▁or ▁sympt oms ▁of ▁the ▁dis order . ▁ ▁Di agn osis ▁ ▁A la ▁+ ▁P bg ▁in ▁ur ine ▁ ▁Pre val ence ▁The ▁condition ▁is ▁extremely ▁rare , ▁with ▁fewer ▁than ▁ 1 0 ▁cases ▁ever ▁reported . ▁ ▁See ▁also ▁▁ ▁List ▁of ▁cut aneous ▁conditions ▁ ▁References ▁ ▁External ▁links ▁▁ ▁Category : S kin ▁conditions ▁resulting ▁from ▁errors ▁in ▁met abol ism ▁Category : P orph y rias ▁Category : Aut os om al ▁re cess ive ▁dis orders <0x0A> </s> ▁Pacific ▁Leg al ▁Foundation ▁( PL F ) ▁is ▁a ▁libert arian ▁public ▁interest ▁law ▁firm ▁in ▁the ▁United ▁States . ▁PL F ▁was ▁established ▁for ▁the ▁purpose ▁of ▁def ending ▁and ▁prom oting ▁individual