CRISPR-targeting with single guide RNAs having spacer sequences of GTATGGTCTTTTTCAGGTGA targeting the 5' side and GACGCTCTGATCTGGAACTT targeting the 3' side of a critical region. This resulted in a 358-bp del Chr7: 68744854-68745211 (p.E101Sfs56*). (GRCm38). (J:94077)