APOA1 and obesity due to melanocortin 4 receptor deficiency: Individuals with rs5069 TT genotype and rs1799837 AA genotype were not detected, Secondly, the HDL-C levels are affected by multiple environmental and genetic factors and their interactions, although we have discussed the interactions of six ApoA1 SNPs and obesity on low HDL-C disease, there are still many unclear environmental and genetic factors and their interactions that remain to be detected.