Distribution of apolipoprotein E allele frequencies of the Han Chinese in an iodine-deficient mountainous area

Background: Iodine deficiency is common in the Qinba mountainous area and fetal iodine deficiency disorder (FIDD) is endemic. Our previous study demonstrated that apolipoprotein E (ApoE) was a genetic risk factor for FIDD in the local area.Aim: In order to achieve a better understanding of the aetiology of iodine deficiency-based mental retardation in the Qinba mountainous area, we conducted further studies of ApoE allele frequencies obtained from the local population.Subjects and methods: A total of 818 samples from four counties in the iodine-deficient area were recruited for the study of the ApoE genotype and allele frequencies using the PCR-RFLP method, and were subsequently confirmed by sequencing.Results: The frequencies of ϵ2, ϵ3 and ϵ4 alleles of Han Chinese in Qinba were 9.67%, 81.30% and 9.03%, respectively. Furthermore, no significant differences in the distribution of ApoE (either genotype or allele frequencies) between any two subgroups divided according to location, sex and age (p > 0.05) we...