Refsum disease

Refsum disease is an autosomal recessive neurological disease that results in the over-accumulation of phytanic acid in cells and tissues. It is one of several disorders named after Norwegian neurologist Sigvald Bernhard Refsum (1907 to 1991). The disease typically begins to show symptoms during adolescence, although symptoms may first appear anywhere between infancy and old age, and it is definitively diagnosed by lab tests showing above average serum levels of phytanic acid or through genetic testing. Symptoms include ichthyosis, muscle weakness, anosmia, eye problems and cerebellar ataxia. It is caused primarily by mutations in the PHYH gene, which encodes phytanoyl-CoA hydroxylase, in about 90 percent of cases, or less commonly by mutations in the PEX7 gene. Treatment centers on a phytanic-acid-restricted diet and plasmapheresis. Its ICD-10 code is G60.1.