Red/ET recombineering was used to target a loxP-flanked neomycin cassette into intron 4 along with the TAT:TGT codon mutation in exon 4, resulting in tyrosine to cysteine amino acid substitution at position 97 (Tyr97Cys) which is homologous to the human p.Tyr107Cys variant. Cre-mediated recombination removed the neomycin cassette. Western blot analysis indicates reduced levels of protein in the striatum. (J:231965)