CRISPR/Cas9 technology generated a GAG>AAG mutation in exon 2 resulting in a glutamate to lysine substitution at amino acid 54 (p.E54K). This is a very rare, predicted damaging, missense variant identified in a child with multiple autoimmune disease and possible learning difficulties. This variant has also been found as a heterozygous de novo mutation in a child with autism spectrum disorder. (J:307413)