DOOR Syndrome is an extremely rare, neurometabolic disorder with a progressive natural history. The name DOOR is an acronym for the four cardinal features of this condition, namely, deafness, onychodystrophy, osteodystrophy, and mild to severe mental retardation. The deafness is congenital and sensorineural and is due to malformations of the inner ear or auditory ear. Onychodystrophy or nail malformations include absent, hypoplastic or rudimentary nails, discoloration, and changes in the texture and shape of the finger and toe nails. Skeletal abnormalities are also concentrated at the hands and feet, and include triphalangy, and hypoplasia of digital bones. Mental retardation is associated with seizures, and peripheral polyneuropathy. Patients also have typical facial features, which include large nose, wide nasal bridge, prominent philtrum, arched palate, down-turned corners of the mouth, slight ptosis, convergent strabismus, and other ocular abnormalities. Till date, only about 40 cases of DOOR Syndrome have been reported worldwide. Diagnosis of DOOR Syndrome is made on the basis of the clinical features. The neurological manifestations of the condition have a progressive nature, and the disease, therefore, follows a deteriorative course.

DOOR syndrome is associated with mutations in TBC1D24 gene, which encodes a protein involved in neuronal projections development.