A condition caused by a 520 kb deletion at 16p12.1. It is characterized by developmental delay, craniofacial dysmorphology and congenital heart defects. The disease is chromosome 16p12.1 deletion syndrome, 520kb (MONDO_0007631). Also known as: Recurrent 16p12.1 microdeletion (neurodevelopmental susceptibility locus), chromosome 16p12.1 deletion syndrome, chromosome 16p12.1 deletion syndrome, type 520kb.