Subsequently, homozygous or compound heterozygous variants and/or intragenic deletions within CNTNAP2 were associated with Pitt-Hopkins like syndrome 1 (PTHSL1, MIM#610042), with variable features that included intellectual disability (ID), early seizure onset, regression of language ability, and hyper-breathing patterns (Strauss et al. 2006; Zweier et al. 2009; Smogavec et al. 2016). This evidence concerns the gene CNTNAP2 and Intellectual disability.