1/52. Xanthoma of the temporal bone: a unique case of this rare condition. Xanthoma of the temporal bone is extremely rare; we describe only the fourteenth reported case. Our case is further remarkable because it is the first report of such an occurrence in a patient with familial type III hyperlipoproteinemia. Moreover, while otalgia, infection, hearing loss, and tinnitus were the most common initial symptoms in the previous 13 cases, our patient reported only diplopia, vertigo, and unstable gait. The patient underwent a simple mastoidectomy and debulking, and his diplopia, vertigo, and unstable gait resolved. ( info) |
2/52. Identification of an apolipoprotein(e) variant associated with type III hyperlipoproteinaemia in an indigenous Australian. As a result of testing for lipid and apolipoprotein(e) (apo E) phenotype status of an indigenous Australian community, an apo E variant associated with type III hyperlipoproteinaemia has been identified. Apo E phenotype was determined by analysis of VLDL by isoelectric focusing, and genotype on dna amplified by polymerase chain reaction, using two different restriction enzyme isotyping assays. Phenotypes and genotypes were discordant in samples from two subjects and an abnormal-sized restriction fragment was also observed in their genotyping gel patterns. dna sequencing studies revealed this was due to a single nucleotide deletion, 3817delC, at amino acid 136 on apo E. This resulted in a new reading frame and the premature termination of the apo E protein due to a stop codon (TGA) at nucleotide 4105. The variant apo E null allele showed a recessive mode of inheritance and, in combination with the E2 allele, resulted in the type III hyperlipoproteinaemic phenotype but when inherited with the E4 allele had no marked effect on plasma lipids. ( info) |
3/52. Two Italian kindreds carrying the Arg136-->Ser mutation of the Apo E gene: development of premature and severe atherosclerosis in the presence of epsilon 2 as second allele. BACKGROUND AND AIMS: Type III hyperlipoproteinemia, or dysbetalipoproteinemia, is commonly associated with apolipoprotein e2 homozygosity (Cys112, Cys158). Apo E2-Christchurch (Arg136-->Ser), a rare mutation of the Apo E gene, located in the receptor-binding domain of the protein, has been found to be associated in the vast majority of cases of dysbetalipoproteinemia. methods AND RESULTS: This is the first report of two Italian kindreds carrying the Arg136-->Ser mutation. One family is a four-generation kindred from Genoa (Liguria, italy) with a high rate of mortality due to coronary artery disease: the proband was a 51-year-old woman with previous myocardial infarction and residual angina, severe carotid atherosclerosis, peripheral arterial vascular disease and arterial hypertension. The other family was identified in Palermo (sicily, italy): the proband was an overweight 62-year-old man with a mixed form of hyperlipidemia. The mutation, which was identified by means of Apo E genotyping followed by direct sequencing, co-segregated with the same haplotype in the two families. CONCLUSIONS: The family histories and clinical examinations of these subjects clearly show that the Apo E Arg136-->Ser variant fully expresses a type III phenotype in association with a second allele coding for Apo E2, and only partially in association with a second allele coding for Apo E4. ( info) |
4/52. Lipoprotein glomerulopathy associated with psoriasis vulgaris: report of 2 cases with apolipoprotein e3/3. Lipoprotein glomerulopathy (LPG) is a rare disease, characterized by a special histology, including dilated glomerular capillaries filled with pale-stained and meshlike lipoprotein thrombi. It always presents with proteinuria or nephrotic syndrome. Although hyperlipidemia is not always seen, most patients have type III hyperlipoproteinemia with apolipoprotein (apo) E2/3 phenotyping. Although the clinical feature of LPG is rarely described, LPG associated with other glomerulopathy, including IgA nephropathy, membranous nephropathy, and lupus nephritis, has been documented. Until now, there have been no reports of psoriasis vulgaris associated with LPG. The authors present 2 cases of LPG with apo E3/3 genotyping associated with psoriasis vulgaris. The first patient was a 65-year-old woman who presented with nephrotic syndrome with daily urinary protein loss of 9.05 g and itchy erythematous scaly plaques on her trunk and lower limbs for 1 year. The renal biopsy results showed LPG, and the skin biopsy results showed psoriasis. The second patient was a 50-year-old man with history of psoriasis over his trunk and 4 limbs for 30 years. He also presented with nephrotic syndrome with daily urinary protein loss of 7.55 g. The renal biopsy results also showed LPG. The genotype of apo E showed E3/3, and lipoprotein electrophoresis showed a type III hyperlipoproteinemia-like pattern in both cases. The authors suggest that presence of apo E3/3 genotype cannot rule out the diagnosis of type III hyperlipoproteinemia and LPG. Besides, LPG should be included in the differential diagnosis of psoriatic patients with nephrotic syndrome, especially in Asian patients who show poor response to traditional therapy. Renal biopsy should be performed to make the definitive diagnosis. ( info) |
5/52. Apolipoprotein E1 Lys-146 Glu with type III hyperlipoproteinemia. During the screening of samples obtained from 5 individuals with type III hyperlipidemia, we identified a variant of apolipoprotein (apo) E which exhibited a discrepancy in apo E phenotype showing the E3/E1 isoform on isoelectric focusing (IEF) analysis and E3/E3 on gene analysis. sequence analysis of the dna of the proband that was amplified by PCR and subcloned, revealed a single substitution of one lysine (AAG) for one glutamic acid (GAG) at position 146, thereby adding two negatively charged units to apo E3. This defect had been described only for apo E1 to date (Mann et al. (1989) Clin. Res. 37, 520A (abstract)). In this case, PCR-mediated site-directed mutagenesis was used to identify the structural alterations forming the abnormal E1 genotype in the proband's family. Purified apo E1 Lys-146 Glu showed less than 10% of binding activity to apo B, E receptor on human skin fibroblasts compared with apo E3. This substitution demonstrates that Lys-146 is essential for the binding of apo E to the receptor. ( info) |
6/52. Severe type III hyperlipoproteinemia associated with unusual apolipoprotein E1 phenotype and epsilon 1/'null' genotype. A 60-year-old white male (KH) was diagnosed to suffer from severe type III hyperlipoproteinemia (HLP) and premature cardiovascular disease. Biochemical analysis revealed an unusual apolipoprotein (apo) E phenotype and genotype. All clinical characteristics of type III HLP were present in the patient. His very low density lipoprotein (VLDL) cholesterol to plasma triglyceride (TG) ratio was elevated at 0.97 without therapy which is unusually high (normal ratio about 0.18). By contrast his plasma apo E level was only moderately elevated (6.8 mg dl-1). The patient's apo E migrated in the apo E1 position on isoelectric focusing gels. Chemical modification with cysteamine and treatment with neuraminidase confirmed the presence of two cysteine residues in the patient's apo E and a normal sialylation pattern. pedigree analysis suggested that the patient was a compound heterozygote with one apo epsilon 1 allele and another allele whose product did not appear in the plasma compartment ('null' allele). Direct sequencing of polymerase chain reaction (PCR) amplified segments of the apo E gene as well as restriction fragment length polymorphism (RFLP) analysis with the endonuclease Taq I identified an adenosine for guanosine (G-->A) exchange in the second base of codon 127 that is predictive for an Asp for Gly substitution in the encoded apo E amino acid sequence. This mutation is the structural basis for the apo E1 isoform identified upon isoelectric focusing. Five other family members are also carriers of the mutant apo epsilon 1 allele. Two of those were hyperlipidemic and exhibited biochemical characteristics of type III HLP. A second mutation, a deletion of a G in codon 31, is predictive for a reading frameshift that encodes for a premature stop in codon 60. Our inability to identify the product of a second apo E allele in the plasma of the patient and two other members of the KH family corresponds with the heterozygous presence of this mutation in the affected individuals. Both relatives (like the index case) had an increased VLDL cholesterol to plasma TG ratio, which indicates the presence of cholesterol-enriched VLDL particles. We propose that the single base deletion in the apo E gene which is the cause of a non-functional 'null' allele in addition to a probably dominant apo E1 (Gly127-->Asp, Arg158-->Cys) variant of late or incomplete penetrance are the primary genetic defects in this kindred leading to severe dysbetalipoproteinemia. ( info) |
7/52. Response to therapy of a type III hyperlipoproteinemic subject with the rare apolipoprotein E1 (Gly127 Asp, Arg158 Cys) variant. In a preceding paper, we described the molecular biological defects in a patient with a severe form of the familial lipoprotein disorder type III hyperlipoproteinemia (HLP) and an unusual apolipoprotein (apo) E1 phenotype and epsilon 1/"null" genotype. The index case was a 60-year-old white male of German ancestry who suffered from a myocardial infarction at age 50 years. He had distinctly elevated levels of plasma lipids (triglycerides 551 mg/dl and cholesterol 747 mg/dl, respectively) and typical clinical signs of this inborn error of lipoprotein metabolism. His mutant apo E1 was shown to be identical to a rare (already described) apo E1 (Gly127 Asp, Arg158 Cys) variant. A second independent defect at the molecular level was a nucleotide deletion of a guanosine (G) in the codon for amino acid 31 of the proband's apo epsilon 3 allele. This single base deletion (not described before) changed his apo epsilon 3 allele to a nonfunctional "null" allele devoid of a stable gene product. Here we describe the response to combined dietary and medical treatment of the patient with this unusual form of type III HLP. His response to therapy was excellent, similar to patients with "classical" type III HLP and homozygosity for apo E2. However, the correct diagnosis of this familial lipoprotein disorder seems to be necessary, even in patients without the expected apo E2/2 phenotype, in terms of the prompt and beneficial response to therapeutic interventions. ( info) |
8/52. Familial dysbetalipoproteinemia in three patients with apoE 2*(Arg136-->Cys) gene variant. Apolipoprotein E (apoE) is a polymorphic protein which occurs in three common isoforms and more than 25 rare variants. Some of the rare apoE variants have been implicated in a dominant mode of inheritance of familial dysbetalipoproteinemia (FD). We have identified three unrelated apoE 2*(Arg136-->Cys) carriers with FD. This finding supports the notion that although apoE 2*(Arg136-->Cys) mutation is perhaps not sufficient to cause FD itself, the presence of other genetic and/or environmental factors can lead to the phenotypic expression of the disease in the carriers. ( info) |
9/52. Type III hyperlipoproteinemia exaggerated by Sheehan's syndrome with advanced systemic atherosclerosis: a 28-year clinical course. A 38-year-old Japanese woman was admitted to hospital for further examination of systemic xanthomas. She had a past history of genital bleeding during her third delivery at the age of 21 years. She was diagnosed with Sheehan's syndrome. Her serum total cholesterol and triglyceride concentrations were 500 and 898 mg/dl, respectively. She was also diagnosed as having type III hyperlipoproteinemia on the basis of the presence of a broad-beta-band on agarose gel electrophoresis and extremely high concentrations of very-low-density lipoprotein cholesterol (310 mg/dl). The diagnosis was later confirmed by her apolipoprotein E isoforms (E2/E2) and genotypes (epsilon2/epsilon2). Thyroid and corticosteroid hormone replacement therapy cured the xanthomas, but also elevated her blood pressure. The serum concentration of intermediate-density lipoprotein cholesterol was consistently high, whereas that of low-density lipoprotein cholesterol was relatively low during the follow-up. Coronary atherosclerosis had already developed by the age of 38 years, and progressed significantly over the following 28 years. Severe stenotic lesions were observed in the bilateral renal arteries and carotid arteries, and in the abdominal aorta when she was 66 years old. These findings suggest that the continuous elevation of intermediate-density lipoprotein cholesterol for a long period contributed to the development of the atherosclerotic lesions. ( info) |
10/52. Discovery and consequences of apolipoprotein-epsilon(3Groningen): a G-insertion in codon 95/96 that is predicted to cause a premature stop codon. BACKGROUND: We found an unexplained, persistent discrepancy between the outcomes of two apolipoprotein-E (apo-E) genotyping methods for a patient with features of familial dysbetalipoproteinaemia (FD). polymerase chain reaction - restriction fragment length polymorphism resulted in the apo-epsilon(2)/epsilon(2) genotype, whereas minisequencing indicated apo-epsilon(2)/epsilon(3). The discrepancy was predicted to derive from a novel mutation.methods: Sequencing of patient dna, set-up of a mutation analysis method and establishment of mutation occurrence in 19 family members of the proband and investigation of its association with serum lipid indices.RESULTS: Sequencing demonstrated a G-insertion in codon 95 or 96 ((95)AAG-(96-)GAG-->(95)AAG-(96)GGA-G) of the apo-epsilon(3) allele. The mutation, designated apo-epsilon(3Groningen), was predicted to cause a frameshift, a premature stop codon at codon 146 (AAG-->TAA) and the expression of a truncated apo-E protein, if any. Four family members with the apo-epsilon(3Groningen) were identified. Two family members with apo-epsilon(3)/epsilon(3Groningen) had serum lipid indices within reference ranges but low-serum apo-E. Three subjects with apo-epsilon(2)/epsilon(3Groningen), proband included, had serum cholesterol, triglycerides and calculated low-density lipoprotein-cholesterol levels above the reference ranges. Their electrophoresis pattern showed the classical broad-beta band, indicative of FD.CONCLUSION: Apo-epsilon(3Groningen) heterozygosity is unlikely to precipitate FD, unless provoked by compound apo-epsilon(2) heterozygosity or other FD precipitating factors. ( info) |