▁that ▁cause ▁the ▁formation ▁of ▁the ▁loop ▁allow ▁the ▁alpha ▁sub unit ▁to ▁hydro ly ze ▁G M 2 ▁gang li os ides ▁into ▁G M 3 ▁gang li os ides ▁by ▁removing ▁the ▁N - ac et yl gal act os am ine ▁( G al NA c ) ▁resid ue ▁from ▁G M 2 ▁gang li os ides . ▁ ▁Gene ▁mut ations ▁resulting ▁in ▁T ay – S ach s ▁disease ▁▁ ▁There ▁are ▁numerous ▁mut ations ▁that ▁lead ▁to ▁hex os amin id ase ▁A ▁def ic iency ▁including ▁gene ▁delet ions , ▁n ons ense ▁mut ations , ▁and ▁miss ense ▁mut ations . ▁ ▁T ay – S ach s ▁disease ▁occurs ▁when ▁hex os amin id ase ▁A ▁los es ▁its ▁ability ▁to ▁function . ▁People ▁with ▁T ay – S ach s ▁disease ▁are ▁unable ▁to ▁remove ▁the ▁Gal NA c ▁resid ue ▁from ▁the ▁G M 2 ▁gang li os ide , ▁and ▁as ▁a ▁result , ▁they ▁end ▁up ▁storing ▁ 1 0 0 ▁to ▁ 1 0 0 0 ▁times ▁more ▁ ▁G M 2 ▁gang li os ides ▁in ▁the ▁brain ▁than ▁the ▁normal ▁person . ▁ ▁Over ▁ 1 0 0 ▁different ▁mut ations ▁have ▁been ▁discovered ▁just ▁in ▁infant ile ▁cases ▁of ▁T ay – S ach s ▁disease ▁alone . ▁ ▁The ▁most ▁common ▁mut ation , ▁which ▁occurs ▁in ▁over ▁ 8 0 ▁percent ▁of ▁T ay – S ach s ▁patients , ▁results ▁from ▁a ▁four