The Refsum's disease in which there is accumulation of phytanic acid is due to defect of

(D) a-oxidation # Ref sum's disease is a rare but severe neurological disorder. The patients of this disease accumulate large quantities of an unusual fatty acid, phytanic acid.> It is derived from phytol, a constituent of chlorophyll.> Hence it is found mostly in plants foods.> However, it is also present in milk lipids and animal fats> Phytanic acid cannot undergo (3-oxidation due to the presence of a methyl group on carbon-3.> This fatty acid undergoes initial a-oxidation to remove the methyl group and this is followed by b-oxidation.> Refsums disease is caused by faulty enzymes during the alpha-oxidation of phytanic acid resulting in buildup of phytanic acid and its unsaturated fatty acid derivatives in the plasma and tissues.> Improved a-oxidation of branched chain fatty acids may be clue to deficiency of Phytanoyl-CoA hydraxylase (or) percxin-7 activities.