The distribution of 17 carbon fatty acids in the liver of a child with propionicacidaemia

A child with propionicacidaemia due to a defective propionyl CoA carboxylase activity, accumulated odd number fatty acids in his liver. Seventeen carbon saturated and monounsaturated acids both represented 2% to 3% of the total liver fatty acids. The monounsaturated acid is demonstrated to be heptadec‐9‐enoic acid. The distribution of the 17 carbon saturated and monounsaturated acids throughout the major lipid classes is described. Enzymic degradation of lecithins and triglycerides is used to establish the positional specificity of esterification of these two fatty acids. The results indicate that when the only difference between two fatty acids, present in similar concentrations, is a single double bond, highly specific esterification patterns are retained.