Refsum disease with increased pipecolic acidemia
Overview
A rare disorder involving all the clinical features of Refsum disease as well as high blood levels of L-pipecolic acid. Refsum disease is a metabolic disorder where a deficiency of phytanic acid alpha-hydroxylase results in a buildup of phytanic acid in the body which causes neurological disorders.
Symptoms
* Progressive nerve deafness * Reduced visual fields * Night blindness * Chronic polyneuropathy * Cerebellar ataxia * Loss of sense of smell * Dry scaly skin * Progressive loss of vision * Pupillary abnormalities * Epiphyseal dysplasia * Clawfoot * Short metacarpal bones * Short metatarsal bones * Cardiomyopathy * Low blood cholesterol * Increased blood phytanic acid level * Thickened nerve sheath * Peripheral neuropathy * Increased protein level in cerebrospinal fluid * Rapid involuntary eye movements * Hypertrophic neuropathy * Cataracts * Neurological deterioration
Treatment
Phytanic acid is almost exclusively of exogenous origin, and dietary restriction reduces plasma and tissue levels.5 Fish, beef, lamb and dairy products should be avoided.22 The average daily intake of phytanic acid is 50–100 mg/day, and ideally this should be reduced to 10–20 mg/day. Phytanic acid is also present in vegetables, but is tightly bound (as phytol) to chlorophyll. Ruminants have the capacity to convert phytol to phytanic acid, and the meat of these animals is thus a significant source of phytanic acid. Diets which are very low in phytanic acid (