The human apolipoprotein E (APOE) gene contains several single-nucleotide polymorphisms (SNPs) that are distributed across the gene. The genotype of the APOE gene has important implications as a risk factor for various diseases. We observed 2 cases in which the results of allele-specific PCR (AS-PCR) of the APOE gene were not consistent with those of fluorescence resonance energy transfer (FRET) or sequencing analysis. In these cases, genotyping by AS-PCR showed that patients were epsilon2 homozygotes, while sequencing analysis and FRET showed that they were epsilon2/epsilon3 heterozygotes. Herein, we describe the causes of the errors in genotyping and describe the significance of these errors.
Alleles ; Apolipoprotein E2/genetics ; Apolipoprotein E3/genetics ; Apolipoproteins E/*genetics ; *Fluorescence Resonance Energy Transfer ; Genotype ; Homozygote ; Humans ; *Polymerase Chain Reaction ; Polymorphism, Single Nucleotide ; Risk Factors ; *Sequence Analysis, DNA

BACKGROUNDLipoprotein glomerulopathy (LPG) is a renal disease characterized by thrombus-like lipoproteins in the glomerular capillaries and its abnormal lipoprotein profiles with marked elevation of apolipoprotein E (apoE). In this study, 15 Chinese patients with LPG were involed in exploring the association of the genetic variation and its plasma level in the pathogenesis of LPG.

METHODSA retrospective analysis of the clinical and pathological features was made in 15 patients with LPG. Plasma concentrations of apoE were measured with radial immunodiffusion assay. Genetic variations of apoE gene were detected using polymerase chain reaction and restriction fragment length polymorphism. Glomerular deposition of apoA, apoB and apoE in these patients were detected by immunofluorescence staining using monoclonal antibodies.

RESULTSBiochemical profiles of lipids and lipoproteins revealed markedly elevated levels of triglyceride, apoB and apoE, but approximately normal levels of total cholesterol, apoA1 and lipoprotein(a) [Lp(a)], which resembled familial hypertriglyceridemia. Genetic analysis demonstrated that the genotype distribution of apoE were 7 cases with epsilon3/epsilon4, 4 cases with epsilon3/epsilon3 and 2 cases with epsilon2/epsilon3. The other 2 cases (a mother and her son) showed a same distinct band. The band pattern of later 2 cases was quite similar to the apoE variant of Tokyo type. The calculated allele frequency of epsilon 4 was relatively high in cases with LPG in comparison with that in the normal controls. We further divided the 13 patients into three groups according to their genotypes of apoE. Patients with the genotype of apoE epsilon2/epsilon3 showed a lower level of plasma apoE as compared to those with apoE epsilon3/epsilon4 (P < 0.05). The serum level of high-density lipoprotein (HDL) was the lowest in patients with the genotype of apoE epsilon3/epsilon4. No difference was found among the patients with different apoE genotype in the other clinical and pathological characteristics.

CONCLUSIONSThe genotype of apoE epsilon3/epsilon4 is the predominant one in Chinese patients with LPG. Patients with this genotype tend to have a higher plasma level of apoE and more severe lipid dysmetabolism. No correlation was found between the genotype of apoE and the clinical features in patients with LPG.

Adolescent ; Adult ; Apolipoprotein E2 ; Apolipoprotein E3 ; Apolipoproteins E ; blood ; genetics ; Child ; Female ; Genetic Variation ; Genotype ; Humans ; Kidney Diseases ; blood ; genetics ; pathology ; Kidney Glomerulus ; blood supply ; pathology ; Lipoproteins ; metabolism ; Male ; Middle Aged

OBJECTIVETo investigate apolipoprotein E(apoE) polymorphism and its relationship with serum lipids and apolipoprotein, serum high density lipoprotein (HDL) subclasses in patients with hyperlipidemia(HL).

METHODSAPOE genotype was assayed by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP). The subclasses of serum HDL in 112 patients with hyperlipidemia and 73 healthy subjects were determined by two-dimensional gel electrophoresis in conjunction with immunodetection method.

RESULTSAPOE3/3 genotypes and allele epsilon3 frequency in HL group and control group were both the highest. In HL group, the genotype of APOE2 had higher serum APOE/CIII ratio and lower HDL3b levels, compared with the genotype of APOE3 (P<0.05). In control group, the genotype of apoE2 had higher serum triglycerides, APOE levels and APOE/CIII ratio, compared with the genotype of APOE3 and APOE4 (P<0.05).

CONCLUSIONPolymorphism of APOE gene may relate to the distribution of HDL particles.

Adult ; Aged ; Apolipoprotein E2 ; Apolipoprotein E3 ; Apolipoproteins E ; blood ; genetics ; Cholesterol ; blood ; Female ; Gene Frequency ; Genotype ; Humans ; Hyperlipidemias ; blood ; genetics ; Lipoproteins, HDL ; blood ; classification ; Male ; Middle Aged ; Polymerase Chain Reaction ; Polymorphism, Restriction Fragment Length ; Triglycerides ; blood

OBJECTIVEThe aim of the study was to investigate apolipoprotein(apo) E polymorphism and its relationship with serum lipids and apolipoprotein, serum high density lipoprotein(HDL) subclasses in patients with type IV hyperlipidemia.

METHODSapoE genotype was assayed by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP). The subclasses of serum HDL in 103 patients with type IV hyperlipidemia and 146 normolipidemic subjects were determined by two-dimensional gel electrophoresis in conjunction with immunodetection method.

RESULTSThe apoE3/3 genotype frequency and allele epsilon 3 frequency were both the highest in the frequency distribution profiles of the type IV hyperlipidemia group and the control group. In type IV hyperlipidemia group, the genotype of apoE2 had higher serum HDL-C,apoE, HDL(2a) apoE/apoCIII ratio but lower TG/HDL-C,apoCIII, HDL(3c) levels when compared with the genotype of apoE(3) (P<0.05). In control group, the genotype of apoE(2) had higher serum TG, apoE levels and apoE/aopCIII ratio but lower HDL (3a) level when compared with the genotype of apoE(3) (P<0.05).

CONCLUSIONAn association of allele epsilon 2 of apoE gene with the maturation of HDL in type IV hyperlipidemia was noted in the study.

Adult ; Aged ; Apolipoprotein C-III ; blood ; Apolipoprotein E2 ; blood ; genetics ; Apolipoprotein E3 ; blood ; genetics ; Apolipoproteins E ; blood ; genetics ; Cholesterol, HDL ; blood ; Female ; Humans ; Hyperlipoproteinemia Type IV ; blood ; genetics ; Lipoproteins, HDL ; blood ; Male ; Middle Aged ; Polymerase Chain Reaction ; Polymorphism, Genetic ; Polymorphism, Restriction Fragment Length ; Triglycerides ; blood

We report the case of a patient who experienced extreme recurrent gestational hyperlipidemia. She was diagnosed with partial lipoprotein lipase (LPL) deficiency but without an associated LPL gene mutation in the presence of the apolipoprotein E3/2 genotype. This is the first reported case of extreme gestational hyperlipidemia with a partial LPL deficiency in the absence of an LPL gene mutation and the apolipoprotein E 3/2 genotype. She was managed with strict dietary control and medicated with omega-3 acid ethyl esters. A patient with extreme hyperlipidemia that is limited to the gestational period should be considered partially LPL-deficient. Extreme instances of hyperlipidemia increase the risk of acute pancreatitis, and the effect of parturition on declining plasma lipid levels can be immediate and dramatic. Therefore, decisions regarding the timing and route of delivery with extreme gestational hyperlipidemia are critical and should be made carefully.
Acute Disease ; Adult ; Apolipoprotein E2/*genetics ; Apolipoprotein E3/*genetics ; Biological Markers/blood ; Combined Modality Therapy ; Diet, Fat-Restricted ; Fatty Acids, Omega-3/therapeutic use ; Female ; Fluid Therapy ; Genetic Predisposition to Disease ; Humans ; Hyperlipoproteinemia Type I/blood/diagnosis/enzymology/*genetics/therapy ; Lipids/blood ; Lipoprotein Lipase/genetics ; Pancreatitis/diagnosis/*etiology/therapy ; Parenteral Nutrition, Total ; Phenotype ; Pregnancy ; Pregnancy Complications/blood/diagnosis/enzymology/*genetics/therapy ; Recurrence ; Tomography, X-Ray Computed ; Treatment Outcome