Methionine codon 143 (ATG) in exon 2 was changed to valine (GTG) (p.M143V) using an sgRNA (targeting TTCAATGCTTGAAGACCCTTNGG) and an ssODN template with CRISPR/Cas9 technology. The mutation is the equivalent of the human p.M144V mutation, in the intrinsically disordered region (IDR), associated with non-photosensitive trichothiodystrophy (NP-TTD). (J:338438)