Development and application of DNA tip for the diagnosis of atherogenic hypertriglyceridemia

点击翻译按钮获取中文摘要

Mild hypertriglyceridemia (type IV hyperlipoproteinemia) is frequently identified in Japanese and is thought to be one of risk factors for heart disease. Mild hypertriglyceridemia results from superimposition of environmental factors, such as high alcohol intake and a hyperinsulinemic state, on a genetic state of a heterozygous mutation in the lipoprotein lipase (LPL) gene. Identification of heterozygote LPL gene mutations as an early determination of etiology underlying mild hypertriglyceridemia, therefore, is important for preventing the development of hypertriglyceridemia and subsequent development of heart disease by getting the patient to change to a more healthful lifestyle. Identification and collection of various LPL gene mutations are essential for the development ofDNA diagnostic tip for analysis ofLPL gene mutations. Results obtained at this (Research Project are listed bellow.(1) We developed an ELISA for the quantification of human LPL mass using two kinds of monoclonal an … More tibodies raised against human LPL, and improved method for direct DNA sequencing of the human LPL gene using an Auto DNA sequencer.(2) We newly identified LPL gene mutations, such as G105R, F270L, G154V and a T-to-C transition in the invariant GT at position +2 of the 5' donor splice site (5'-dss) ofintron 8 (Int8/5'-dss/t (+2) c) from Japanese subjects with mild hypertriglyceridemia. Also, we identified a mutation of D204E reported elsewhere. In missense mutations ofG105R, F270L, G154V and D204E, all mutants LPL expressed in COS-1 cells were catalytically inactive. Subjects with heterozygous LPL deficiency (carriers) are prone to develop type IV hyperlipoproteinemia when complicated with factors such as a hyperinsulinemic state and/or a high alcohol intake, which stimulate triglyceride synthesis in the liver, while carriers are normolipidemic provided that they do not have factors leading to hypertriglyceridemia.(3) So far, we have collected 15 mutations of the LPL gene by our Research projects including this project. Among 15 mutations, we have succeeded in identifying five mutations of Try-61-Stop, Asp-204-Glu, Ala-221-del, Ala-261 -Thr and Trp-382-Stop using Invader assay system (DNA diagnostic chip). Less