CRISPR/Cas9 technology generated a G to A change at position 978 (c.978G>A) resulting in a glutamate to lysine substitution at amino acid 256 (p.E256K). This corresponds to a disease-associated mutation seen in patients with the rare autosomal recessive neurodevelopmental disorder spastic tetraplegia, thin corpus callosum, and progressive microcephaly. (J:344184)