LEC: Lipid-Cardiac Function Tests Part 2 Flashcards
Associated with defective apoB synthesis or metabolism, leading to low or nonexistent levels of apo-B lipoproteins such as CM, VLDL and LDL
Isolated Low Total Cholesterol
Which does not belong to the group?
Abetalipoproteinemia
Hypobetalipoproteinemia
Familial Hypoalphalipoproteinemia
Chylomicron retention disease
Familial Hypoalphaproteinemia
Premature degradation of apoB due to defects in
the hepatic microsomal transport protein, which
is essential for apoB secretion. And neither apoB-48 or apoB-100 is present in the plasma
Abetalipoproteinemia
Causes fat soluble vitamin deficiencies (A, E, K) due to
malabsorption.
Abetalipoproteinemia
This vitamin does not require
chylomicrons for absorption and therefore is not
typically deficient
Vitamin D
Nonsense or missense mutations in the apoB
gene leading to very low LDL-C levels
Hypobetalipoproteinemia
Hypobetalipoproteinemia can be treated with?
high dose vitamin E (100-300
mg/kg/day)
Disorder where only B-48 is affected and is associated with SARA2 gene on chromosome 5q3
Chylomicron retention disease
Total cholesterol levels in homozygous individuals with hypobetalipoproteinemia
<50 mg/dL
Associated with CHD because insufficient HDL is available to participate in reverse cholesterol transport,
the process by which cholesterol is eliminated from peripheral tissue
Isolated Low HDL-C
What are the disorders associated with isolated low HDL-C?
- Familial hypoalphalipoproteinemia
- ApoA-1 deficiency and ApoC-III deficiency
- ApoA-1 variants
- Tangier disease
- Lecithin: Cholesterol Acyltransferase (LCAT) deficiency
Disorder where there is hepatic lipase or apoA-I/C-III/A-IV gene defects and mutations in the ABCA1 gene. Premature CHD is also present
Familial Hypoalphaproteinemia
IDENTIFY:
- Autosomal recessive. Mutations in the ApoA-1 gene and deletions. Gene rearrangements at the apoA-1/C-III/A-IV gene locus on the long arm of chromosome
11
ApoA-1 deficieny and ApoC-III deficiency
IDENTIFY:
- Amino acid substitution in the ApoA-1 gene
- Increase catabolism of HDL and ApoA-I
ApoA-1 variants
It is autosomal dominant and the only disorder in isolated low HDL-C that is not associated with premature CHD
ApoA-1 Milano
IDENTIFY:
- Autosomal recessive
- Low cholesterol and high triglycerides
- ABCA1 protein enables cholesterol to exit the
cell where it combines with ApoA-I to form the
HDL. In the absence of ABCA1 activity,
cholesterol accumulates in cells
Tangier disease
Without this, most cholesterol remains unesterified and HDL synthesis is impeded
LCAT
IDENTIFY:
- HDL-C levels are <10 mg/dL
- Total cholesterol are normal to high
Classic (complete) familial LCAT deficiency
Form of LCAT deficiency that is associated with premature CHD
Partial deficiency (Fish-eye disease)
In familial hypoalphaproteinemia, Men have HDL-C levels ______ and women have HDL-C levels _______
<30 mg/dL and <40 mg/dL, respectively
