Using CRISPR/cas9 endonuclease mediated genome editing, single guide RNAs are designed to create a C-to-T nucleotide replacement (CGA-to-TGA) encoding an arginine 539-to-termination codon nonsense mutation (R539X). This mutation corresponds to the R542X mutation identified in the patient population as a disease causing variant in Congenital Disorders of Glycosylation Type 1v.