Essential fatty acids in clinically stable children with propionic acidaemia.

Disturbances of fatty acid metabolism with accumulation of odd-chain fatty acids have been reported in propionic acidaemia (PA). It is not known whether the synthesis of long-chain polyunsaturated fatty acids (LCPUFA) is also affected. In five clinically stable children with PA (median age 8 years, range 3.5-9.5 years; median percentage fibroblast propionyl-CoA carboxylase activity 0.8, range 0.8-1.5), we determined the fatty acid composition of plasma phospholipids, triglycerides and sterol esters and compared the results with those of 18 age-matched healthy controls. Odd-numbered fatty acids were found in all samples of PA patients but in controls median values were zero. Percentage contributions of substrate (linoleic acid, C18:2 omega-6) and principal product (arachidonic acid, C20:4 omega-6) of omega-6 LCPUFA synthesis did not differ between patients and controls. Similarly, there were no differences between both groups in the substrate (alpha-linolenic acid, C18:3 omega-3) and principal product (docosahexaenoic acid, C22:6 omega-3) of omega-3 LCPUFA formation. We conclude that disturbances of fatty acid metabolism in clinically stable children with PA do not affect LCPUFA synthesis.