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. The gene discussed is STAG1; the disease is neurodevelopmental disorder.