Duane syndrome type 3 is a disorder of eye movement.The affected eye, or eyes, has limited ability to move both inward toward the nose and outward toward the ears. The eye opening narrows and the eyeball pulls in when looking inward toward the nose. About 15 percent of all cases of Duane syndrome are type 3. Most cases occur without other signs and symptoms.In most people with Duane syndrome type 3, the cause is unknown; but it can sometimes be caused by mutations in the CHN1 gene and inherited in an autosomal dominant fashion. The disease is Duane retraction syndrome 3 with or without deafness (Monarch Disease Ontology term MONDO_0014880). Also known as: DURS3, Duane retraction syndrome caused by mutation in MAFB, MAFB Duane retraction syndrome.