- Chorea-acanthocytosis (Ch-Ac) is a rare neurodegenerative movement disorder. It is an autosomal recessive disease caused by mutations in the Vacuolar Protein Sorting 13 Homolog A (VPS13A) gene, encoding for chorein . The clinical phenotype is classically characterized by choreiform movements, psychiatric disorder and cognitive impairment. A polyneuropathy, a myopathy or an isolated increase in creatine kinase (CK) levels are often detectable and epilepsy can worsen the neurological conditions of Ch-Ac patients.
- Vascular parkinsonism (VP) is estimated to account for 2.5–5% of all cases of parkinsonism . It is commonly caused by vascular lesions of the brainstem, basal ganglia, and white matter of the frontal lobes; there are two known causes: 1) acute forms due to infarcts in strategic areas that directly increase basal ganglia output or decrease the thalamocortical drive; 2) progressive forms with insidious onset caused by extensive subcortical white matter lesions. Because of its mixed heterogeneity, VP is not a well-defined neurological entity.
- DOOR is the acronym of a rare autosomal recessive syndrome characterized by congenital deafness, onychodystrophy, osteodystrophic lesions of finger and/or toe bones, and mental retardation. Mental retardation represents the less constant feature of the syndrome; it is suggested that the association of deafness with nail or finger abnormalities should indicate a possible diagnosis of DOOR syndrome .