Animal studies (on transgenic and knock-out mice) and human association analysis assessed the importance of APOAV gene for plasma triglyceride determination. New APOAV missense variants (Val153 → Met and Cys185 → Gly) have been detected recently. We have analyzed these variants in 83 unrelated patients with extreme lipid parameters (triglycerides of 20.4±12.8 mmol/l and total cholesterol of 10.4±3.7 mmol/l) and in a control population group consisting of 2,559 unrelated Caucasians. In patients, the frequency of the Met153 carriers was slightly but not significantly higher (9.64 % vs. 6.49 %) compared to the population sample. This suggested that Val153 → Met polymorphism in the APOAV gene does not represent an important risk factor for developing the extreme levels of plasma triglycerides. We did not detect carriers of the Gly185 allele among patients or 420 healthy individuals. We suppose that this variant is probably not present in Caucasian populations.