This allele from project TCPR1460 was generated at The Centre for Phenogenomics by electroporating Cas9 ribonucleoprotein complexes with single guide RNAs having spacer sequences of GTTTAAGGGCATTCTCACCC targeting the 5' side and GTTGATAGACTGGGCAAGAC targeting the 3' side of a critical region. This resulted in a 1290-bp del Chr3:35789082-35790371 (GRCm38).