BAD LUCK: An Extremely Rare Mutation Landed a Woman in Prison For Murder. “Twenty years ago, Kathleen Folbigg was imprisoned, having been found guilty of killing her four children. A few days ago, she received a full pardon and walked free. A mutation in a CALM gene that affects one in 35 million people is now thought to have caused the deaths of her two daughters via a rare syndrome called calmodulinopathy.”