Lipid composition and lipolytic activities in milk from a patient with homozygous familial hypobetalipoproteinemia.

We have investigated the composition of breast milk from a patient with abetalipoproteinemia. Activity level and specific activity of lipoprotein lipase in milk samples obtained at 0.5 and 3 mo postpartum were higher than those found in normal milk; activity of bile salt-activated lipase was found to be higher in the milk at 6 mo postpartum than in normal milk but average specific activity of this enzyme in milk samples was not increased. Except for higher protein content of patient's milk, there was no apparent abnormality in the protein pattern as determined by SDS-polyacrylamide gel electrophoresis. Lipid analysis indicated a shift in the molecular weight distribution of triglycerides, which favored lower molecular weight forms and reflected an increase in medium-chain and a major decrease in long-chain essential fatty acids (omega 6 and omega 3) in milk triglycerides.