Monarch Disease Ontology entry MONDO_0013646 (chromosome 8q21.11 deletion syndrome) is heterozygous overlapping microdeletions on chromosome 8q21.11 resulting in intellectual disability, facial dysmorphism comprising a round face, ptosis, short philtrum, Cupid's bow and prominent low-set ears, nasal speech and mild finger and toe anomalies. Also known as: 8q21.11 microdeletion syndrome, Del(8)(q21.11), chromosome 8q21.11 deletion syndrome, isolated cases, deletion 8q21.11, monosomy 8q21.11.