This allele from project TCPR1331 was generated at The Centre for Phenogenomics by electroporating Cas9 ribonucleoprotein complexes with single guide RNAs having spacer sequences of ATTGTTTTGAGACGAGACTT and ATCACCATGCCGGTCCCAAT targeting the 5' side and ACTGGGCGAGCAGGTTACGT and TCGCCCTCAAGATTACTTCC targeting the 3' side of a critical region. This resulted in a 521-bp del Chr11:55218714-55219234; 23-bp del Chr11:55219287-55219309_insGAG (GRCm38).