MSTN / PrP double mutations in cell colony make the target locus resistant to Van91I and Bsu36I treatment (arrowhead). (journals.plos.org)
Of nine colonies with MSTN / PrP double mutations, five colonies had biallelic mutations of both genes. (journals.plos.org)
If both parents have cystic fibrosis, for example, any offspring would inherit the disease — it's a so - called autosomal recessive disorder, which means an affected person has mutations in both copies of the key gene, and all children of an affected couple would also carry double mutations. (sciencemag.org)