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Refsum disease

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Definition

noun

A genetic disorder resulting in the accumulation of the fatty acid phytanic acid in cells and tissues, which, in turn, results in diminishing vision, polyneuritis, and cerebellar ataxia


Supplement

Refsum disease is a genetic disorder that is inherited in an autosomal recessive pattern. The individual that has Refsum disease has two copies of the defective gene that is essential in producing proteins for normal phytanic acid metabolism. The absence of a functional enzyme phytanic acid α-hydroxylase leads to the accumulation of phytanic acid, which in turn leads to a number of progressive problems. Some of these problems are polyneuritis (i.e. inflammation of numerous nerves), diminishing vision (due to retinitis pigmentosa), and wobbliness (ataxia) caused by damage to the cerebellar portion of the brain (cerebellar ataxia). Ichthyosis may also manifest.

Mutation in PHYH gene is one of the causes of Refsum disease. In humans, the gene codes for phytanoyl-CoA hydroxylase. This enzyme is needed for the alpha-oxidation of fatty acids, such as phytanic acid, in peroxisomes. Defective PHYH gene could impair the production of this enzyme. As a result, phytanic acid accumulates. Another gene associated with the disease is a defective PEX gene, which codes for the peroxin enzyme. PEX7 gene, in particular, codes for the perozin 7 protein receptor.

Refsum disease is named after Sigvald Bernhard Refsum, a Norwegian neurologist.


Variant:

  • Refsum's disease

Synonym(s):

  • Refsum syndrome
  • phytanic acid oxidase deficiency
  • heredopathia atactica polyneuritiformis
  • phytanic acid storage disease

See also: