title: Differential diagnosis of Huntington's disease: what the clinician should know.
abstract: Huntington's disease (HD), an autosomal-dominant illness caused by an expansion of the CAG repeats on the short arm of chromosome 4, is clinically characterized by a combination of movement disorders, cognitive decline and behavioral changes. HD accounts for 90-99% of patients who present with this clinical picture. The remaining patients that are negative for the HD genetic mutation are said to have HD phenocopies. Autosomal-dominant diseases that can mimic HD are HD-like 2, C9orf72 mutations, spinocerebellar ataxia type 2, spinocerebellar ataxia type 17 (HD-like 4), benign hereditary chorea, neuroferritinopathy (neurodegeneration with brain iron accumulation type 3), dentatorubropallidoluysian atrophy and HD-like 1. There are also autosomal-recessive choreas that can be HD phenocopies: Friedreich's ataxia, neuroacanthocytosis, several forms of neurodegeneration with brain iron accumulation, ataxia telangiectasia, HD-like 3 and ataxia with oculomotor apraxia. Among X‑linked conditions, McLeod syndrome can mimic the clinical features of HD. Although less frequently, sporadic conditions, such as tardive dyskinesia and non-Wilsonian hepatolenticular degeneration, can also mimic HD.
authors.affiliation: Neurology Service, Department of Internal Medicine, The Federal University of Minas Gerais, Belo Horizonte, Minas Gerais, Brazil. cardosofe@terra.com.br.
authors.forename: Francisco
authors.initials: F
authors.lastname: Cardoso
mesh_terms: D003937:Diagnosis, Differential; D005799:Genes, Dominant; D005808:Genes, Recessive; D050172:Genes, X-Linked; D005820:Genetic Testing; D006801:Humans; D006816:Huntington Disease / Q000175:diagnosis* / Q000453:epidemiology / Q000235:genetics / Q000503:physiopathology; D010641:Phenotype