This study will determine whether short term intravenous infusion of vitamins A and E in patients with abetalipoproteinemia can reverse disease symptoms in these patients. Abetalipoproteinemia is an inherited metabolic defect that prevents fat-soluble vitamins, such as A and E, from being absorbed from the intestines into the bloodstream and from being secreted by the liver. The deficiencies of vitamins A and E can result in severe vision impairment and a gait disorder. Treatment with megadoses of these vitamins, taken by mouth, may delay or arrest symptoms, but many continue to progress.

For this study, a single patient with moderately severe eye and neurological defects will be given essential fatty acids and fat soluble vitamins directly through a vein (intravenously) using FDA-approved replacements with a fat emulsion and multivitamins containing fat-soluble vitamins. This route of administration will bypass the digestive tract, where the absorption problem occurs. The infusions will be given twice a week for one month and then weekly for another month. Blood tests will be done weekly to measure blood lipids (fatty acids and other substances), cell counts, and vitamin levels. Eye and neurological examinations will be done once a month.

The cases of two sisters with abetalipoproteinemia are reported. Both presented the complete clinical and biological features of the disease: ataxia, retinitis pigmentosa, lack of apolipoprotein B, chylomicrons, LDL and VLDL, reduced titers of serum cholesterol and triglycerides, acanthocytosis, very low levels of serum vitamin A and E. Abetalipoproteinemia is a rare autosomal inherited disease. It is usually revealed during early childhood by steatorrhea and failure to thrive; ataxia and retinitis pigmentosa appear later. The originality of these two cases stems from: 1) their late and fortuitous diagnosis: the first sister was investigated at the age of 42 after the discovery of a vitamin K induced coagulation disorder. The other sister was 39 when she was routinely examined as a family member; 2) the presence of constipation without any other suggestive digestive complaint. However, white discoloration of the duodenal mucosa seen at endoscopy and lipid droplets within the intestinal absorptive cells at biopsy were characteristic. Barium studies showed diffuse involvement of the small bowel which was displaced by an enlarged sigmoid. Treatment consists of administration of vitamin A and vitamin E which prevent or delay ocular and neurologic symptoms. Vitamin K is associated whenever necessary.

A 26-year old male suffered from Abeta-lipoproteinemia (Bassen-Kornzweig disease). In addition to C.N.S. lesions, he had myopathy. A muscle biopsy revealed accumulation of ceroid pigment in the striated muscle. A few muscle fibers showed severe degeneration of the myofibrils. Fibroblasts and macrophages in the interstitial tissue contained abundant ceroid. The relation between ceroid accumulation, abetalipoproteinemia and vitamin E-deficiency is discussed.

OBJECTIVE:

Description of rickets as an unexpected initial manifestation in two children with abetalipoproteinemia and hypobetalipoproteinemia, and elucidation of its pathophysiology in these conditions.

METHODOLOGY:

Two infants aged two and six months with abetalipoproteinemia and hypobetalipoproteinemia respectively had clinical rickets at presentation, confirmed radiologically and biochemically. Vitamin D intake and serum levels were measured and other causes of rickets were looked for.

RESULTS:

Vitamin D intake and laboratory studies levels were suggestive of rickets due to calcium deficiency instead of vitamin D deficiency. Healing of rickets occurred with dietary treatment of the malabsorption, without any dietary calcium or significant vitamin D supplementation.

CONCLUSION:

Steatorrhea-induced calcium malabsorption seems to be the most likely cause of rickets in this entity.

A case of oxalate lithiasis associated with Abetalipoproteinemia is reported. The excessive absorption of dietary oxalate in this patient with fat malabsorption occurs because unabsorbed fatty acids in the bowel lumen combine with calcium ions which would otherwise impair oxalate absorption by forming insoluble calcium oxalate crystals. The medical management include dietary fat restriction and supplements of the fat soluble vitamins A, E and K. The prognostic is poor particularly in the neurological and retinal component of this disease.

We report a probable case of abetalipoproteinemia in an infant who presented with unusual symptoms of late-onset vitamin K deficiency. Abetalipoproteinemia is a rare autosomal recessive disease caused by mutation of the microsomal triglyceride transfer protein gene, resulting in the absence of microsomal triglyceride transfer protein function in the small bowel. It is characterized by the absence of plasma apolipoprotein B-containing lipoproteins, fat malabsorption, hypocholesterolemia, retinitis pigmentosa, progressive neuropathy, myopathy, and acanthocytosis. A biopsy of the small intestine characteristically shows marked lipid accumulation in the villi of enterocytes. Large supplements of fat-soluble vitamins A, D, E, and K have been shown to limit neurologic and ocular manifestations. Dietary fat intake is limited to medium-chain triglycerides.

AIM:

To investigate the pituary, genitalia, adrenal, thyroid, parathyroid and pancreatic endocrine function of a female patient aged 37 with abetalipoproteinemia at the time of diagnosis and 5 years thereafter (after application of a modified diet).

SUBJECT-METHODS:

Serum concentrations of cortisol, A4, ACTH, aldosteron, renin, dehydroepiandrosterone sulfate (DHEA-5), progesterone, 17-OH progesterone, testosterone, SH13G, estradiol, luteinizing hormone, follicle stimulating hormone, T3, T4, TSH, FT3, FT4, parathormone, osteocalcin, prolactin, proinsuline, insulin, glucagon, somatomedin-C (Insulin-like Growth Factor-1, IGF-1), IG171-13P3, 25 (OH) Vitamin D3 and 1-25 (OH) 2 Vitamin D3, were measured by radioimmunoassay. Synactlien test, and 24-hour urine cortisol, were also estimated. Serum leptin estimation was carried-out using a sensitive enzymatic technique. Ionized part of serum calcium was measured by the use of a special machine (CORNING), while bone alkaline phosphatase was measured by radioimmunoassay.

RESULTS:

Serum progesterone and 17-OH-progesterone were reduced in both examinations. Estimation of serum progesterone performed on the 21th day of the menstrual cycle revealed again values below the lowest normal limit. Serum prolactin was increased both in rest and during movement. The levels of both, somatomedin-C (IGF-1) and leptin were below the lowest normal limit. Despite normal serum parathormone, serum-ionized calcium and 25-OH vitamin D were low, while serum bone alkaline phosphatase was increased. Serum proinsulin was increased, and serum insulin was low. Serum thyroid hormone, glucagon, parathormone, FSH, LH, ACTH, testosterone, estradiol and SH13G were normal. The hormonal profile of the patient estimated 5 years later did not differ substantially suggesting that the metabolic improvement due to the adoption of the modified diet had not any significant impact on it.

CONCLUSION:

Female patients with abetalipoproteinernia have reduced production of progesterone by the corpus luteum and slightly abnormal bone metabolism. The reduced production of progesterone is probably due to the low levels of serum LDL and cholesterol, while reduced serum levels of Leptin and IG17-1 are probably due to the impairment nutritional status. The adoption of a modified diet does not alter the hormonal profile significantly.

BACKGROUND:

Abetalipoproteinemia is a rare disorder of fat absorption, characterized by vitamin deficiency, acanthocytosis, and neurologic symptoms including ataxia and tremor.

CASE REPORT:

A 41-year-old male with abetalipoproteinemia is presented. He underwent staged bilateral thalamic deep brain stimulation (DBS) for the treatment of his tremors. After DBS, the patient achieved significant improvements in his tremors, ataxia, and quality of life.

DISCUSSION:

Thalamic DBS proved to be both safe and efficacious in the management of ataxia and tremors in a patient with abetalipoproteinemia. This is the first report of DBS in abetalipoproteinemia in the literature.

Abetalipoproteinaemia (ABL) is an autosomal recessive disorder characterized by very low plasma concentrations of total cholesterol and triglyceride (TG). It results from mutations in the gene encoding microsomal TG transfer protein (MTTP). A nine-month-old girl was admitted to hospital because of fever, cough, diarrhea and failure to thrive. She had low cholesterol and TG levels according to her age. The peripheral blood smear revealed acanthocytosis. Thyroid function test showed central hypothyroidism. Cranial magnetic resonance imaging revealed the retardation of myelination and pituitary gland height was 1.7 mm. A homozygous novel mutation [c.506A>T (p.D169V)] was detected in the MTTP gene. Vitamins A, D, E, and K and levothyroxine were started. The coexistence of ABL and central hypothyroidism has not previously been reported. A homozygous novel mutation [c.506A>T (p.D169V)] was detected in the MTTP gene.

The effect of peroxidative stress on tissue was studied by exposure of red blood cells (RBC) from patients with abetalipoproteinemia to minute amounts of H(2)O(2)in vitro. Red blood cells from untreated patients showed a marked sensitivity to H(2)O(2), as evidenced by hemolysis and lipid peroxidation (peroxidative hemolysis). The appearance of lipid peroxidation products in sensitive cells after exposure to H(2)O(2) was indicated by 1) increases in the 2-thiobarbituric acid (TBA) reaction of trichloroacetic acid extracts, 2) increases in ultraviolet light absorbency of lipid extracts, and 3) decreases in polyunsaturated fatty acids. These changes were accompanied by a decrease in phosphatidyl ethanolamine and phosphatidyl serine in the RBC lipid extract. Similar lipid changes on exposure to H(2)O(2) were observed in the RBC from vitamin E-deficient rats. Treatment of the patients with d-alpha-tocopherol polyethylene glycol succinate by mouth, or addition of dl-alpha-tocopherol to the incubation medium protected the RBC from peroxidative hemolysis. Tocopherol appears to provide a primary biologic defense against peroxidative hemolysis. The presence of nitrite or carbon monoxide, which produced methemoglobin and carboxyhemoglobin, respectively, inhibited peroxidative changes, suggesting a catalytic role for oxy- or deoxyhemoglobin. Substances that prevented lipid peroxidation also prevented hemolysis; in addition, lipid peroxidation appeared to precede hemolysis. These observations suggested that hemolysis was a consequence of lipid peroxidation.