The molecular lesion, created using CRISPR/Cas9 technology, is a substitution of an A with a TG doublet in exon 2 (c.164delAinsTG, mRNA sequence GenBank NM_026511), which generates a frameshift resulting in a truncated protein (p.Asp55Valfs*20). Skeletal muscle and liver mRNA levels were reduced to 25% and 50%, respectively.