CNTNAP2 and autism spectrum disorder: CASPR2 has also been identified as a synaptic protein with a role in synapse development/maintenance and has recently been linked to neurodevelopmental processes (Rodenas-Cuadrado et al., 2014): humans with homozygous loss-of-function mutations in CNTNAP2 (the gene encoding CASPR2) develop epilepsy and developmental delay with a number of core features of autistic spectrum disorder (ASD) (Strauss et al., 2006).