Autor(es):
Medeiros, A.M. 
; Santos, T. ; Alves, A.C. ; Bourbon, M.
Data: 2011
Identificador Persistente: http://hdl.handle.net/10400.18/378
Origem: Repositório Científico do Instituto Nacional de Saúde
Assunto(s): Doenças Cardio e Cérebro-vasculares
Descrição
APOE gene is polymorphic, comprises three frequent alleles (e2, e3, e4) which create six different genotypes and six protein isoforms with different affinity to LDLR. Isoform E2 has less affinity to receptor while isoform E4 have much efficient bond and compete with apoB.
The present study pretends to evaluate the distribution of APOE alleles/genotype of index patients with clinical diagnosis of Familial Hypercholesterolemia (FH) and investigate if a specific allele/genotype is cause of hypercholesterolemia.
APOE genotyping was performed using SnaPShot Multiplex System after PCR amplification. Biochemical parameters were determined by routine methods and results were analyzed with SPSS software using t- test.
For this analysis, children and adults were divided according to their genetic diagnosis. Total of 353 patients were analyzed: 140 patients with mutation in LDLR, APOB or PCSK9 (44 children (G1), 96 adults (G2)) and 213 without a detectable mutation (70 children (G3), 143 adults (G4). Distribution of 6 genotypes (E2/E2, E2/E3, E2/E4, E3/E3, E3/E4, E4/E4) was as following: G1, 0%, 2.3%, 4.5%, 68.2%, 20.5%, 4.5%; G2, 1.0%, 1.0%, 4.2%, 62.5%, 28.1%, 3.1%; G3, 0%, 1.4%, 5.7%, 55.7%, 35.7%, 1.4%; G4, 0%, 1.4%, 5.6%, 63.5%, 25.9%, 3.5%. Statistical analysis revealed that presence of at least one e4 is associated with high levels of LDLc in G3/G4 patients (LDLcG3=182.96±49.46mg/dl, (e4/eX, X=2,3,4) vs LDLcG3=152.65±60.60mg/dl (eY/eZ, Y,Z=2,3), p=0.025; LDLcG4=227.69±43.17mg/dl, (e4/eX, X=2,3,4) vs LDLcG4=179.70±64.78mg/dl (eY/eZ, Y,Z=2,3), p<0.001)) but not in G1/G2 patients (p=0.100, p=0.832).
Presence of e4 can be the cause of hypercholesterolemia presented by patients without genetic diagnosis of FH.
