Type I hyperlipoproteinaemia and recurrent scrotal pain

A three-year-old boy is described with type I hyperlipoproteinaemia in association with recurrent scrotal pain and hepatosplenomegaly. His parents are consanguinous and it is likely that he is homozygous for an autosomal recessive trait, characterized by the absence of plasma lipoprotein lipase following intravenous injection of heparin. Studies have been performed in a number of first degree relatives, but the findings are inconclusive. He has responded well to a low fat diet with dramatic reductions in elevated plasma triglyceride concentrations.