Alpha oxidation

Pathway.
Alpha-oxidation of phytanic acid is believed to take place entirely within peroxisomes. 
Deficiency.
Enzymatic deficiency in alpha-oxidation (most frequently in phytanoyl-CoA hydroxylase) leads to Refsum's disease, in which the accumulation of phytanic acid and its derivatives leads to neurological damage. Other disorders of peroxisome biogenesis also prevent alpha-oxidation from occurring.