Ans. A (H DL) HDL contains good cholesterolQ So there is an inverse relation between HDL concentration and coronoary heart disease. This is consistent with the function of HDL in reverse cholesterol transport. Diseases (eg. diabetes mellitus, lipid nephrosis, hypothyroidism and other conditions of hyperlipedimea) in which prolonged elevations of VLDL, IDL, LCD or chylomicron remnants in blood are often accompanied by premature or severe atherosclerosis0. This makes LDL : HDL cholesterol ratio a good predictive for atherosclerosis & coronary heart disease.Frederickson Classification of Hyper LipoproteinemiasPhenotypeIIIaIIbIIIIVVLaboratory FeaturesLipoprotein, elevatedChylomicronsQLDLQLDL and VDLChylomicrons and VLDL remnantsVLDLChylomicrons and VLDLTriglycerides++++--++++ to ++++++++++Cholesterol+ to +++++Q++ to +++++ to +++-- to +++ to +++LDL-cholesterol||||||HDL-cholesterol+++++++++++++Plasma appearanceLactescentClearClearTurbidTurbidLactescentClinical FeaturesXanthomasQEruptiveTendon, tuberousNonePalmar, tuberoeruptiveNoneEruptivePancreatitis+++0000+++Coronary atherosclerosis0++++++++++/-+/-Peripheral atherosclerosisQ0+++++/-+/-Molecular defect & Genetic nomenclatureMolecular defectsLPL and apo-C-IILDL receptor. ApoB-100, PCSK9, ARK, ABCGS and ABCG8UnknownApoEApoA-V and UnknownApoA-V and UnknownGenetic nomenclatureFCSFH.FDB, ADH, ARH, sitos-terolemiaFCHLFDBLFHTGFHTG- FCS (familial chyiemicrofiemia syndrome) - FDB (familial defective apo B) - FH (familial hypercholesterolemia) - ARH (autosomal recesive hypercholesterolemia) - ADH (autosomaldominant hypercholesterolemia) - FCHL (familial) combined hyperlipidemia) FDBL (familial dysbetalipoproteinemia) - FHTG (familial hypertriglyceridemia). - LPL (lipoprotein lipase) - Apo (apolipopretien)