Glutamic acid codon 348 through proline codon 353 in exon 4 were deleted (c.1042_1059del, p.E348_P353delEDTSQP) using an sgRNA and an ssODN template with CRISPR/cas9 technology. The mutation is in the T-box and includes five human TBR1 variants identified as pathogenic or likely pathogenic. (J:339271)