OBJECTIVETo investigate the effects of Apo A1 and B gene polymorphism on avascular necrosis of the femoral head (ANFH) in north Chinese Han population.

METHODSPolymerase chain reaction-restriction fragment length polymorphisms (PCR-RFLP) technique was used in samples of 143 cases with documented ANFH and 92 healthy control matched by age and sex individuals selected from north Chinese Han nationality. The studied loci include promoter region (-75bp) and the intron 1 (+83 bp) of Apo A1 gene, Eco RI,Xba I of Apo B gene; polymerase chain reaction was used to study 3'-VNTR of Apo B gene.

RESULTSAt -75 bp in promoter, the frequency of A/A genotype in ANFH group was significantly higher than that in control group (P < 0.01), while the frequency of G/A genotype in ANFH group was significantly lower than that in control group (P < 0.01). No difference was found in the frequency of genotype at +83bp in intron 1 of Apo A1 gene, Eco RI, Xba I and 3'-VNTR loci of Apo B gene.

CONCLUSIONApolipoprotein A1 gene A/A substitution at position -75 in promotor is associated with ANFH, the mutation may be one of the sensitive genes of ANFH, first reported inside and abroad. But no evident relationship was found between gene polymorphism of +75 bp loci of Apo A1 gene, Eco RI loci of Apo B gene, Xba I loci of Apo B gene or 3'-VNTR of Apo B gene and ANFH.