This allele from project TCPR1475 was generated at The Centre for Phenogenomics by electroporating Cas9 ribonucleoprotein complexes with single guide RNAs having spacer sequences of CAGCGCACTCGGGTCCGGTG targeting the 5' side and GCACAACTGGGGTGGTACAT targeting the 3' side of a critical region. This resulted in a 4992-bp deletion Chr1:181831344-181836335 (GRCm38).