Very rare. Autosomal recessive transmission.Except for the accumulation of phytanic acid, it has no relation with infantile Refsum disease. Anomaly of the α-oxidation of phytanic acid (PAHX or PHYH or PEX 7 gene on 6q22q24 and 10pter-p11.2), leading to its accumulation. 

The main signs of the disease are:

-         retinitis pigmentosa: amblyopia, nystagmus, cataract

-         peripheral polyneuropathy: walking disorders, sometimes amyotrophy and distal sensory disorders.

One can also find cerebellar ataxia, deafness and/or an anosmia but intelligence is normal. Sometimes: ichthyosis, disorders of cardiac conduction (progressive heart failure cases has been reported), epiphyseal dysplasia.

Only one third of the cases occurs before the age of 10 years. 

Treatment: diet avoiding exogenous sources of phytanic acid: dairy products, fish, beef, lamb.

Anesthetic implications: 

preoperative cardiac evaluation (ECG); monitoring the curarization taking amyotrophy in account, protection of nerve compression sites (large nerves).

References : 

Updated: October 2018