Type-I hyperlipoproteinemia is characterized by

Primary Hyperlipoproteinaemias:Frederickson et al. (1967) proposed five types based on changes in plasma lipoproteins.1. Type-I: Familial Lipoprotein Lipase Deficiency:A rare disorder and is characterised by Hyperiglyceridaemia (TG |), and hyperchylomicronaemia. Chylomicrons grossly increased || and there is slow clearing of chylomicrons.VLDL (Pre-b-Lipoproteins) also increased, more so in, increased carbohydrate intake.Decrease in a-lipoprotein (HDL|) and b lipoproteins (LDL|).Inheritance: Autosomal recessive.Enzyme deficiency:Deficiency of the enzyme lipoprotein lipase.A variant of the disease can be produced by deficiency of apo-C II.Clinical feature: Presents in early childhood and is characterised byEruptive XanthomasRecurrent abdominal pain.NoteDisease is fat induced. Patient may be effectively treated by low dietary fat.High carbohydrate diet can raise Pre-b-lipoprotein levels as TG synthesis in Liver increases.Premature cardiovascular disease is not encountered. Refrigeration test:If serum of suspected patient is taken in a narrow small tube and kept in refrigerator temperature for 24 hrs undisturbed, a clear zone of chylomicrons is seen to float on the top and make a distinct separate layerRef: Textbook of Medical Biochemistry, 8th Edition, Dr (Brig) MN Chatterjea, Rana Shinde, page no: 451