The fact that expression patterns of the cPcdh genes are compromised in CTCF ADA mutation, Nipbl, and SA1 depletion or mutation, along with the prominent cPcdh brain-wiring function, suggest that the dysregulation of cPcdh genes resulted from defective cohesin processivity may underlie the pathogenesis of various neurodevelopmental disorders of cohesinopathy. This evidence concerns the gene ADA and neurodevelopmental disorder.