Lipoprotein Disorders

Question 1

Type I: Familial LPLase Deficiency

Answer 1

Cause: 1a: LPLase deficiency, 1b: abnormal LPLase production, 1c: ApoCII Deficiency
Result: High TAG (mainly Chylomicrons), low HDL
Sx:
Tx:
Dx:
Keywords: Risk Factors: Primary: Genetic.; Secondary: Diet, bodily factors (obesity), or other factors: diabetes I, environemntal, & smoking

Question 2

Type 2: Familial Hypercholesterolemia

Answer 2

Cause:2a: Defective LDL Receptor; 2b: Polymorphism of Apo CII, APO CIII & CETP
Result: 2a: high LDL (cholesterol), high TAG (VLDL), low HDL
Sx: High cholesterol in plasma, Xanthomas (cholesterol nodule under skin & tendons), esp high risk of atherosclerosis due to high LDLs
Tx: Cholestrylamine (bile squesterant), HMG-CoA reductase (Statin), Niacin
Keywords: $ classes of LDL receptor defects

Question 3

Type 3: Hyperlipidemia

Answer 3

Cause: Abnormal ApoE which interferes with hepatic CM & VLDL uptake
Result: High TAG (IDL & CM remnants), low HDL

Question 4

Type 4: Hypertriglyceridemia

Answer 4

Cause: overproduction of VLDL
Result: High TAG (mainly VLDL), low HDL
Keywords:Similar to type 1 but with high VLDL and CM

Question 5

Type 5

Answer 5

Cause: Decreased LPLase (something wrong with it), hgih VLDL, 
Result: high TAG (VLDL and CM), low HDL
Sx:
Tx:
Dx:
Keywords:

Question 6

Tangier’s Disease

Answer 6

Cause: ABC transporter gene > less transporter
Result: Inability of cells to transfer XS cholesterol to HDLs > low plasma HDL, low LDLs, 1/3 normal (bc no CEPT transfer from VLDL to HDL, CM normal, VLDL high (Hypertriglyceridemia)
Sx: Cholesterol accumulation in extrahepatic tissues (esp. reticuloepithelial system), engorged macrophages accumulate in lymphoid tissues such as the tonsils
Tx: Diet & lfestyle, plus drug therapy
Dx:
Keywords:

Question 7

Familial LCAT deficiency (Associated with HDL)

Answer 7

Cause: Lecithin: cholesterol acyltransferase (LCAT) reduces the level of free cholesterol, regulates composition of plasma lipoproteins & indirectly cholesterol content of membranes.

Question 8

Wolman’s Disease

Answer 8

Cause: Lysosomal Storage Disease; deficiency of lysosomal Acid Lipase (in childhood)
Result: Unable to break down old cholesteryl esters and TAG
Sx: Accumulation of cholesteryl esters and TAG in the Lysosomes, hepatosplenomegaly, mild mental retardation
Keywords: Death before 6 months!!

Question 9

Abetalipoproteinemia (Bassen-Kornweig syndrome)- Hypolipoproteinaemia

Answer 9

Cause: Defect in Apo-B expression (no CM, VLDL, or LDL)
Result: lipid malabsorption, fatty liver and intetines, ataxic neuropathic disease
Sx:
Tx:
Dx:
Keywords:

Question 10

Familial Hypobetalipoproteinaemia

Answer 10

Cause: 20 different Apo variants, low VLDL and LDL, HDL normal
Result:Sx: Asymptomatic