致ち死し突とつ然ぜん変へん異いちしとつぜんへんいMeanings1nounlethal mutationgeneticsTechnical term in genetics for a mutation that causes death of the organism.この系けい統とうは致ち死し突とつ然ぜん変へん異いを持もつため、ホモ接せつ合ごう体たいは生せい存ぞんできない。Because this strain carries a lethal mutation, homozygotes cannot survive.