Pallidal degeneration, progressive, with retinitis pigmentosa (hypoprebetalipoproteinemia, acanthocytosis, retinitis pigmentosa, and pallidal degeneration; harp syndrome)

General: Autosomal recessive; destruction of global pallida and reticular portions of substantia nigra; also may be associated with hypoprebetalipoproteinemia and acanthocytosis; various combinations of components of HARP syndrome may be caused by several distinct genetic diseases or may represent variable manifestations of a contiguous gene defect.

Ocular: Retinitis pigmentosa.

Clinical: Progressive extrapyramidal rigidity; dysarthria.

Higgins JJ, et al. Hypoprebetalipoproteinemia, acanthocytosis, retinitis pigmentosa, and pallidal degeneration (HARP syndrome). Neurology 1992; 42:194-l98.

McKusick VA. Mendelian Inheritance in Man; A Catalog of Human Genes and Genetic Disorders, 12^th ed. Baltimore: The Johns Hopkins University Press, 1998.

Online Mendelian Inheritance in Man, OMIM. McKusick-Nathans Institute for Genetic Medicine, Johns Hopkins University and National Center for Biotechnology Information, National Library of Medicine, February 12, 2007. World Wide Web URL: https://www.ncbi.nlm.nih.gov/omim/.

Orrell RW, et al. Acanthocytosis, retinitis pigmentosa, and pallidal degeneration: a report of three patients, including the second reported case with hypoprebetalipoproteinemia (HARP syndrome). Neurology 1995; 45[3 Part 1]: 487-492.

Winkelman NW Progressive pallidal degeneration: a new clinicopathologic syndrome. Arch Neurol Psychiatry 1932; 27:1-21.