Cases reported "Hypobetalipoproteinemias"

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1/58. A study of fatty liver disease and plasma lipoproteins in a kindred with familial hypobetalipoproteinemia due to a novel truncated form of apolipoprotein B (APO B-54.5).

    BACKGROUND/AIMS: Familial hypobetalipoproteinemia (FHBL) is a co-dominant disorder characterized by reduced plasma levels of low-density lipoproteins. It can be caused by mutations in the gene encoding apolipoprotein b-100 (apo B), leading to the formation of truncated apo Bs which have a reduced capacity to export lipids from the hepatocytes as lipoprotein constituents. case reports suggest the occurrence of liver disease in FHBL, but there are no studies of liver involvement in FHBL with defined apo B gene mutations. The presence of fatty liver disease was investigated in a large FHBL kindred. methods: plasma lipoprotein and apolipoprotein analysis, liver function tests, and apo B gene sequence were performed in 16 members of a FHBL kindred. The presence of fatty liver was assessed by ultrasound and computed tomography scanning. RESULTS: The proband, a non-obese heavy drinker male with hypobetalipoproteinemia, had steatohepatitis with fibrosis. He was heterozygous for a novel non-sense mutation of apo B gene producing a truncated apo B of 2745 amino acids (designated apo B-54.5, having half the size of normal apo B-100). Seven other members of his kindred carried apo B-54.5. Although all of them were hypolipidemic, their lipid levels showed a large inter-individual variability not accounted for by polymorphisms of genes involved in apo B metabolism. Four carriers (two heavy drinkers and two teetotallers), irrespective of their plasma lipid levels, had ultrasonographic evidence of fatty liver. In the other four carriers no evidence of fatty liver was found. CONCLUSIONS: In this kindred apo B-54.5 predisposes to fatty liver, which however may require some additional factors to become clinically relevant.
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2/58. rickets as an unusual initial presentation of abetalipoproteinemia and hypobetalipoproteinemia.

    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.
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ranking = 0.63174440613244
keywords = lipoprotein, deficiency
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3/58. Clinical characterization of a case with familial hypobetalipoproteinemia caused by apo B-76, a new truncation of apolipoprotein B, combined with apo E2/E2 phenotype.

    We report a 43-year-old Japanese man with hypobetalipoproteinemia likely due to apolipoprotein (apo) B-76, a new truncation of apo B, and with homozygosity for the apo E2 isoform. He had no history suggestive of fat malabsorption and no sign of neurological disorder. His fasting baseline serum low-density lipoprotein (LDL) cholesterol and apo B levels were approximately half of normal. His plasma apo E level was elevated and its phenotype showed the E2/E2 homozygote. SDS-polyacrylamide gel electrophoresis of delipidated LDL fraction revealed a new truncated apo B, designated as apo B-76 according to the centile system of nomenclature. The postprandial lipid metabolism of the patient showed an almost normal response after fat loading.
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ranking = 0.57894736842105
keywords = lipoprotein
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4/58. Acanthocytosis in a patient with homozygous familial hypobetalipoproteinemia due to a novel APOB splice site mutation.

    We report on acanthocytosis in a 31-year-old woman with homozygous familial hypobetalipoproteinemia due to a mutation affecting the splicing of the APOB gene encoding apolipoprotein B. Treatment with fat-soluble vitamins was associated with arrest of the usually progressive neurological complications of this condition. However, the acanthocytosis - literally 'thorny' erythrocytes that result from abnormal membrane fluidity - persists despite treatment.
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ranking = 0.31578947368421
keywords = lipoprotein
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5/58. Gene-drug interaction: additive influence of mutant APOA1 and testosterone on plasma HDL-cholesterol.

    OBJECTIVES: Factors associated with decreased plasma high-density lipoprotein (HDL) cholesterol concentration, or hypoalphalipoproteinemia, include androgenic steroids and mutations in APOA1, encoding apolipoprotein (apo) A-I, the main structural protein of HDL. However, there is little information regarding the extent of plasma HDL lowering when exogenous testosterone is used in subjects with monogenic low HDL. DESIGN AND methods: A man with coronary heart disease (CHD) had been receiving exogenous testosterone post-orchidectomy. He had marked hypoalphalipoproteinemia, which was not responsive to diet or medication. To identify a possible genetic contribution to his biochemical phenotype, we sequenced the LCAT and APOA1 genes. RESULTS: There were no sequence abnormalities in LCAT, but we found that he was a heterozygote for a novel APOA1 mutation in codon 107 (AAG->TGG), which predicted the replacement of lysine by tryptophan (K107W). Serial biochemical measurements over 11 years showed that plasma HDL cholesterol on either intramuscular or oral testosterone was 0.19 /- 0.06 mmol/L, while plasma HDL cholesterol on transdermal testosterone was significantly higher at 0.52 /- 0.18 mmol/L (p = 0.015, unpaired t-test). CONCLUSIONS: The findings suggest that the low plasma HDL cholesterol associated with heterozygosity for mutant APOA1 can become extremely depressed during treatment with oral or intramuscular androgens. The findings also suggest that transdermal testosterone may perturb HDL to a lesser extent than other routes of delivery in such patients.
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ranking = 0.21052631578947
keywords = lipoprotein
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6/58. Unusual presentation of three siblings with familial heterozygous hypobetalipoproteinaemia.

    We describe three siblings with the unusual presentation of manifest steatorrhoea and vitamin e deficiency mimicking homozygous familial hypobetalipoproteinaemia (FHBL) but whose lipid profile (cholesterol and ApoB) was consistent with heterozygous FHBL. Upper gastrointestinal endoscopy and small intestinal biopsy were normal. We discuss the diagnosis with reference to the relevant literature. CONCLUSION: although rare, familial hypobetalipoproteinaemia should be considered among the causes of manifest steatorrhoea in childhood even without evidence of failure to thrive. Dietary restriction of fat and high dose vitamin E supplementation improves quality of life by reducing stool frequency and may prevent or delay neurological complications.
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ranking = 0.31587220306622
keywords = lipoprotein, deficiency
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7/58. MCA/MR syndrome with hypocholesterolemia related to familial dominant hypobetalipoproteinemia.

    Recent reports have emphasized the role of cholesterol in vertebrate embryonic development. The RSH or so-called smith-lemli-opitz syndrome (SLOS) was the first multiple congenital anomalies/mental retardation syndrome related to a cholesterol synthesis disturbance. Familial hypobetalipoproteinemia is a well-known dominantly inherited entity in which affected individuals usually are free of symptoms. We report on the unusual association of a malformation syndrome with mental retardation resembling SLOS and profound hypocholesterolemia related to familial hypobetalipoproteinemia. We discuss the possible causal relationship between the two conditions and the current understanding of the role of cholesterol in normal embryogenesis.
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ranking = 0.31578947368421
keywords = lipoprotein
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8/58. Infantile refsum disease: gastrointestinal presentation of a peroxisomal disorder.

    This article describes two siblings with infantile refsum disease (IRD) whose initial presentation was that of malabsorption and mimicked a-beta- or homozygous hypo-beta-lipoproteinemia. Failure to recognize IRD in the first-born child precluded proper genetic counseling and prenatal diagnosis in subsequent pregnancies and also caused considerable delay in diagnosing IRD in the second child. The clinical heterogeneity of peroxisomal disorders constitutes a diagnostic challenge, which demands a high degree of awareness from the part of the clinician. This is particularly the case with IRD, where protracted diarrhea with low serum cholesterol levels appears to be a frequently occurring initial feature during the 1st months of life.
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ranking = 0.052631578947368
keywords = lipoprotein
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9/58. A novel truncated apolipoprotein B (apo B55) in a patient with familial hypobetalipoproteinemia and atypical retinitis pigmentosa.

    We have identified an apolipoprotein (apo) B mutation in a patient with an atypical form of retinitis pigmentosa (RP). In the family the eye disease is characterised by late age of onset and autosomal dominant inheritance. In addition to RP, the proband has low total cholesterol (4.5 mmol/l) and LDL-cholesterol (2.0 mmol/l) levels characteristic of the autosomal codominant apolipoprotein (apo) B deficiency disease hypobetalipoproteinemia (HBL). Using a monoclonal antibody directly against apo B and immunoblots of SDS polyacrylamide gel separated plasma, a normal apo B100 and a truncated apo B species with an estimated size of apo B54 was identified in the proband and his RP-affected sister. The location of the mutation in the apo B gene was identified using chemical cleavage of mismatch and this was confirmed by direct sequencing of an amplified fragment of dna spanning the estimated site of the mutation. The mutation is a C   T transition at nucleotide 7692 which changes the CGA arginine2495 codon to a STOP codon resulting in the premature termination of apo B100. The truncated apo B protein is 2494 amino acids long with a predicted size of apo B55. Using allele specific oligonucleotides and oligonucleotide melting techniques, the proband, his sister and two other relatives out of a total of 20 family members, screened for the presence of the apo B55 mutation, were heterozygous for the mutation. The segregation of the apo B55 allele was confirmed in the family using the 3' variable number of tandem repeats of the apo B gene.(ABSTRACT TRUNCATED AT 250 WORDS)
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ranking = 0.57903009780306
keywords = lipoprotein, deficiency
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10/58. ApoB-75, a truncation of apolipoprotein B associated with familial hypobetalipoproteinemia: genetic and kinetic studies.

    We have identified a mutation of apolipoprotein B (apoB) in a kindred with hypobetalipoproteinemia. Four affected members had plasma concentrations of total cholesterol of 115 /- 14, low density lipoprotein (LDL)-C of 48 /- 11, and apoB of 28 /- 9 (mg/dl mean /- SD). The values correspond to approximately 30% the values for unaffected relatives. Triglyceride and high density lipoprotein (HDL)-C concentrations were 92 /- 50 and 49 /- 4, respectively, neither significantly different from unaffected relatives. Western blots of plasma apoB of affected subjects showed two major bands: apoB-100 and an apoB-75 (mol wt of approximately 418,000). dna sequencing of the appropriate polymerase chain reaction (PCR)-amplified genomic dna segment revealed a deletion of the cytidine at nucleotide position 10366, resulting in a premature stop codon at amino acid residue 3387. In apoB-75/apoB-100 heterozygotes, two LDL populations containing either apoB-75 or apoB-100 could be distinguished from each other by gel permeation chromatography and by immunoblotting of nondenaturing gels using monoclonal antibodies B1B3 (epitope between apoB amino acid residues 3506-3635) and C1.4 (epitope between residues 97-526). ApoB-75 LDL were smaller and more dense than apoB-100 LDL. To determine whether the low concentration of apoB-75 was due to its enhanced LDL-receptor-mediated removal, apoB-75 LDL were isolated from the proband's d 1.063-1.090 g/ml fraction (which contained most of the apoB-75 in his plasma) by chromatography on anti-apoB and anti-apoA-I immunoaffinity columns. The resulting pure apoB-75 LDL fraction interacted with the cells 1.5-fold more effectively than apoB-100 LDL (d 1.019-1.063 g/ml). To determine the physiologic mechanism responsible for the hypobetalipoproteinemia, in vivo kinetic studies were performed in two affected subjects, using endogenous labeling of apoB-75 and apoB-100 with [13C]leucine followed by multicompartmental kinetic analyses. Fractional catabolic rates of apoB-75 VLDL and LDL were 2- and 1.3-fold those of apoB-100 very low density lipoprotein (VLDL) and LDL, respectively. Production rates of apoB-75 were approximately 30% of those for apoB-100. This differs from the behavior of apoB-89, a previously described variant, whose FCRs were also increased approximately 1.5-fold relative to apoB-100, but whose production rates were nearly identical to those of apoB-100. Thus, in contrast to the apoB-89 mutation, the apoB-75 mutation imparts two physiologic defects to apoB-75 lipoproteins that account for the hypobetalipoproteinemia, diminished production and increased catabolism.
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