Familial Apolipoprotein B100 Deficiency
Introduction
Introduction to familial apolipoprotein B100 deficiency Familial deficient protein B100 deficiency (FDB) was first discovered in 1986. When studying patients with moderately elevated plasma cholesterol levels, Vega et al. noted a small number of subjects with low-density lipoprotein (LDL) in vivo. The catabolic rate is slow, and its LDL receptor function is normal, presumably due to abnormalities in the LDL particles themselves. basic knowledge The proportion of illness: 0.00041% Susceptible people: no special people Mode of infection: non-infectious Complications: atherosclerosis, coronary heart disease, hypertension
Cause
The cause of familial apolipoprotein B100 deficiency
(1) Causes of the disease
FDB is due to the replacement of arginine (Arg) at position 3500 in Apo B100 by glutamine (Gin) (Arg3500Gln), resulting in binding of LDL to the receptor containing this defective Apo B100.
(two) pathogenesis
The catabolism of normal plasma lipoprotein is mainly affected by the apolipoprotein contained in it. Since more than 95% of apolipoprotein (Apo) in LDL is Apo B100, it may be due to genetic defects of Apo B100. LDL binds to its receptor, thereby affecting the rate of LDL catabolism in the body. Subsequent studies confirmed this inference, which has been confirmed to be due to the arginine (Arg) at 3500 in Apo B100 being glutamine ( Replacement of Gln) (Arg3500Gln), causing LDL binding to the receptor containing this defect Apo B100, and the function of Apo Bl00 to bind to LDL receptor due to the substitution of amino acids in other parts of Apo Bl00 molecule, Therefore, it has been suggested to use the term FDB3500 to describe the familial apolipoprotein B100 deficiency found by Vega et al. Later, Pulllinger et al found a case of FDB patients whose defects were replaced by amino acids at position 3531 of Apo Bl00. For FDB3531, in addition, Gaffeny et al found a case of FDB3500 patients whose amino acid was not replaced by Gln in the 3500 position, but was replaced by tryptophan. Therefore, it is recommended to use FDB3500Q to express FDB was discovered early, and FDB3500w was used in newly discovered cases. FDB and familial hypercholesterolemia (FH) are hypercholesterolemia caused by LDL catabolic disorders. However, high cholesterol is caused by both. The pathophysiological mechanisms of blood are different. FDB is caused by Apo B genetic defects, ie, defects in ligands, while FH is caused by genetic defects in LDL receptors.
Prevention
Familial apolipoprotein B100 deficiency prevention
1. At present, there is no specific preventive measure for this disease. It is necessary to strengthen the prevention and treatment personnel's understanding of the disease and understand the harm and serious consequences of the disease.
2. Patients with this disease should take the initiative to receive low-fat and low-carbohydrate diet treatment, and timely use appropriate lipid-lowering drugs to adhere to treatment.
3. Patients should regularly check their blood lipids to maintain normal levels.
4. Actively prevent complications.
Complication
Familial apolipoprotein B100 deficiency complications Complications atherosclerosis coronary heart disease hypertension
FDB patients with atherosclerosis (carotid artery, coronary artery, peripheral vascular artery), coronary heart disease, hypertension and other complications.
Symptom
Familial apolipoprotein B100 deficiency symptoms common symptoms high plasma cholesterol levels atherosclerosis diabetes hypertensive dyslipidemia
1. During childhood or adolescence, plasma LDL cholesterol levels have increased significantly, and plasma total cholesterol and low-density lipoprotein cholesterol levels continue to increase with age. However, this elevated age effect has gender differences. After the age of 60, the age effect is weakened.
2. The patient's plasma total cholesterol concentration and LDL-C concentration increased moderately or moderately.
3. High-density lipoprotein cholesterol (HDL-C), very low-density lipoprotein (VLDL-C) and triacylglycerol in patients' plasma are similar to those of normal Apo B100, and are generally normal.
4. Clinical manifestations of atherosclerosis (including carotid artery, coronary artery, peripheral artery, etc.), coronary heart disease, tendon xanthomas, lipid corneal arch, hypertension.
Examine
Examination of familial apolipoprotein B100 deficiency
The plasma cholesterol concentration and the concentration of low density lipoprotein cholesterol are increased moderately or moderately.
No relevant information has been found yet.
Diagnosis
Diagnosis and identification of familial apolipoprotein B100 deficiency
Diagnostic criteria
1. During childhood or adolescence, plasma LDL cholesterol levels have increased significantly, and plasma total cholesterol and low-density lipoprotein cholesterol levels continue to increase with age, but this elevated age effect There are gender differences, and after 60 years of age, the age effect is weakened.
2. The patient's plasma total cholesterol concentration and LDL-C concentration increased moderately or moderately.
3. High-density lipoprotein cholesterol (HDL-C), very low-density lipoprotein (VLDL-C) and triacylglycerol in patients' plasma are similar to those of normal Apo B100, and are generally normal.
4. Clinical manifestations of atherosclerosis (including carotid artery, coronary artery, peripheral artery, etc.), coronary heart disease, tendon xanthoma, lipid corneal arch, hypertension and other manifestations.
Differential diagnosis
Clinically, it is differentiated from familial hypercholesterolemia, hypertriglyceridemia, familial abnormal -lipoproteinemia, and familial mixed hyperlipidemia (Table 3).
