endocrine and metabolic disorders
Hypolipidemia
Abetalipoproteinemia (Bassen Kornzweig syndrome)
This autosomal recessive condition is caused by mutations in the gene for microsomal triglyceride (TG) transfer protein, a protein critical to chylomicron and very-low-density lipoprotein (VLDL) formation. Dietary fat cannot be absorbed, and lipoproteins in both metabolic pathways are virtually absent from serum; total cholesterol is typically<45 mg/dL (<1.16 mmol/L), TGs are<20 mg/dL (<0.23 mmol/L), and LDL is undetectable. is distributed to peripheral tissues via VLDL and LDL, most affected people eventually develop severe Vitamin E Deficiency . Symptoms and signs include visual changes due to slow retinal degeneration, sensory neuropathy, posterior column signs of ataxia and paresthesias, and cerebellar signs of dysmetria, ataxia, and spasticity, which can eventually lead to death. Diagnosis is made by the absence of apoprotein B (apo B) in plasma. Intestinal biopsy specimens show lack of microsomal transfer protein. Red blood cell acanthocytosis is a distinguishing feature on blood smear. Genetic testing can confirm the diagnosis. Treatment ofvitamin Edeficiency is with high doses (100 to 300 mg/kg once a day orally) ofvitamin Ewith supplementation of dietary fat and other fat-soluble vitamins. The prognosis is often poor. 