Serine codon 155 (TCT) in exon 1 was changed to aspartic acid (GAT) (p.S155D) using an sgRNA (targeting GTGCTTTGACCTCCGAAGGAAGG and GACTCTGTCAGCACCTTCTCTGG) and an ssODN template with CRISPR/Cas9 technology. This mutation changes the affected residue in the encoded peptide to a phosphomimetic. (J:338167)