#Biochemistry
Section: Theory
Subject: diseases of fats and lipoproteins
Types:
1. High cholesterol and LDL:
1_ Polygenic (Nonfamilial) Hypercholesterolemia or FH:
Blood cholesterol is high
The cause is family, either from father or mother
The autosomal dominant disease has a mutation on the LDL receptor generating gene (on chromosome 19), so the metabolism becomes problematic and the blood LDL is high.
Fredrickson classification: type 2a
People get premature coronary heart disease (premature coronary heart disease)
A homozygous person is at high risk because he has two defective copies, LDL above 400mg/dl
At the age of 40, he had premature CHD
A heterozygous person has a low risk because he has a broken copy, LDL above 220mg/dl
In men, it shows later, over 40 years old, but in women, it shows as a child
Symptoms: corneal arcus (white ring around the cornea), cholesterol deposition in the eye and around xnthelasma, cholesterol deposition in the tendon Tendinos xanthomata
Treatment: Because cholesterol is high, cholesterol anabolism should be reduced, like statin drugs
Of course, it works in homozygous people, provided that the receptors are not mutated
Heterozygous people do tapheresis
2_familial defective ApoB:
Blood cholesterol is high
The LDL receptor is healthy, but the gene producing ApoB_100 is mutated (Arg3500 is substituted for glutamine)
The symptoms are similar to familial hypercholesterolemia
3_sitosterolemia:
Phytosterols are the same as cholesterol, with the difference that they are produced by plants
The intestines and liver of this sterol are transported (as sediment) using ATP to cause excretion through feces
Transports: BCG5 and ABCG8
So the mutation in these two causes an increase in phytosterols
Early cardiovascular problems
1_ Polygenic (Nonfamilial) Hypercholesterolemia:
If the increase in cholesterol is due to the 3 high cases that I mentioned, from this model, even if the person follows a diet, he exercises, but the cholesterol is still high.
High blood cholesterol
The cause is non-familial and polygenic (several factors play a role in the occurrence of this disease)
This disease is very common
Symptoms: Eruptive xanthomas
2. Normal cholesterol and high TG:
1_Lipoprotein lipase deficiency:
Autosomal recessive disease
The lipoprotein lipase enzyme is not produced, the metabolism of VLDL and Chylomicron is disturbed and these two increase.
It usually shows symptoms like pancreatic symptoms such as heartache
The amount of TG is 10000mg/dl
If TG is high, they have liver and fatty liver
If Chol is high, it is also cardiovascular
Fredrickson classification: type 1
2_ApoC-2 deficiency:
Absence of this effector + for the effect of LPL causes an increase in chylomicrons
Pancreatic problems such as heartache
3_ApoC-3 excess:
The expression of this effector inhibits the activity of LPL, causing an increase in chylomicrons
4_ familial hypertriglyceridaemia
Autosomal dominant disease
Almost common
Its pathogenesis is idiopathic (unknown).
It is called swollen VLDL because the amount of TG and VLDL is high, so it is rich in TG
So TG, VLDL is too much
Fredrickson classification: type 4
3. High cholesterol and TG:
1_ Dysbetalipoproteinemia:
Autosomal recessive disease
One of the causes of that is the mutation in the gene that produces ApoE
ApoE has 3 isozymes that bind to LDL receptor in terms of strength
ApoE3>ApoE1>ApoE2
Of course, ApoE2 is not related
Therefore, the mutation in ApoE3 remains the increase of chylomicrons, and cholesterol and TG are naturally high.
2_Hepatic lipase deficiency:
Liver LPL enzyme is defective, not complete
Cholesterol is high and naturally TG is high
3_ Familial Combined Hyperlipidemia:
Hereditary and compound disease
The expression of ApoB_100 is high in VLDL and LDL
Fredrickson classification: type 2b
4. Low cholesterol and TG:
‼ Frediskon only said so and so many things, but he rejects this 4th case
1_ Abetalipoproteinemia:
In this disease, we don’t have ApoB_100 at all, so the lipoproteins that don’t have this Apo in their structure are not made at all and their amount is low.
One of the causes is a mutation in the gene that produces the protein
(MTP) microsomal triglyceride transfer protein
In fact, the job of this protein is to take TG to the endoplasmic reticulum and attach it to ApoB_100, but if TG does not join Apo, Apo will be degraded.
2_Hypobetalipoproteinemia:
A truncation mutation occurs in the generating gene of ApoB_100, so its values are low
5. Low HDL:
1_Tangir:
Mutations in the ABCA1 generator gene
2_ LCAT deficiency:
It will not be made at all
It is quite clear that HDL is not made spherical
3_Fish eye:
LCAT enzyme is made defective
Cholesterol deposition in fish eye-like eyes
Compared to the second one, it is less risky
@Probe_Lab
This post is written by Amer_7798