Familial chylomicronemia (type I hyperlipoproteinemia) due to a single missense mutation in the lipoprotein lipase gene.
نویسندگان
چکیده
Complete deficiency of lipoprotein lipase (LPL) causes the chylomicronemia syndrome. To understand the molecular basis of LPL deficiency, two siblings with drastically reduced postheparin plasma lipolytic activities were selected for analysis of their LPL gene. We used the polymerase chain reaction to examine the nine coding LPL exons in the two affected siblings and three relatives. DNA sequence analysis revealed a single nucleotide change compared with the normal LPL cDNA: a G----A substitution at nucleotide position 680. This transition caused a replacement of glutamic acid for glycine at amino acid residue 142 of the mature LPL protein. Amino acid sequence comparisons of the region surrounding glycine-142 indicated that it is highly conserved among lipases from different species, suggesting a crucial role of this domain for the LPL structure. Expression studies of the mutant LPL cDNA in COS-7 cells produced normal amounts of enzyme mass. However, the mutated LPL was not catalytically active, nor was it efficiently secreted from the cells. This established that the Gly----Glu substitution at amino acid 142 is sufficient to abolish enzymatic activity and to result in the chylomicronemia syndrome observed in these patients.
منابع مشابه
Molecular basis of familial chylomicronemia: mutations in the lipoprotein lipase and apolipoprotein C-II genes.
The molecular basis of familial chylomicronemia (type I hyperlipoproteinemia), a rare autosomal recessive trait, was investigated in six unrelated individuals (five of Spanish descent and one of Northern European extraction). DNA amplification by polymerase chain reaction (PCR) followed by single strand conformation polymorphism (SSCP) analysis allowed rapid identification of the underlying mut...
متن کاملPremature atherosclerosis in patients with familial chylomicronemia caused by mutations in the lipoprotein lipase gene.
BACKGROUND Patients with lipoprotein lipase deficiency usually present with chylomicronemia in childhood. The syndrome has been considered nonatherogenic primarily because of the low levels of low-density lipoprotein (LDL) cholesterol. We prospectively evaluated patients with lipoprotein lipase deficiency for atherosclerosis. METHODS Evidence of carotid, peripheral, and coronary atheroscleros...
متن کاملA single Ser259Arg mutation in the gene for lipoprotein lipase causes chylomicronemia in Moroccans of Berber ancestry.
Lipoprotein lipase (LPL) is the rate-limiting enzyme for the hydrolysis of triglyceride-rich lipoproteins. Numerous LPL gene mutations have been described as a cause of familial chylomicronemia in various populations. In general, allelic heterogeneity is observed in LPL deficiency in different populations. However, a founder effect has been reported in certain populations, such as French Canadi...
متن کاملA case report of 5 y/o girl with familial chylomicronemia
Background: Familial chylomicronemia syndrome is a rare disorder of lipoprotein metabolism due to familial lipoprotein lipase or apolipoprotein C-II deficiency or the presence of inhibitors to lipoprotein lipase. It manifests as eruptive xanthomas, acute pancreatitis, and lipaemic plasma due to marked elevation of triglyceride and chylomicrons levels. Case presentation: We report a rare case of...
متن کاملFamilial chylomicronemia in a nine months old infant.
Familial chylomicronemia syndrome is a rare disorder of lipoprotein metabolism due to familial lipoprotein lipase or apolipoprotein C-II deficiency or the presence of inhibitors to lipoprotein lipase. It manifests as eruptive xanthomas, acute pancreatitis, and lipaemic plasma due to marked elevation of triglyceride and chylomicrons levels. We report a rare case of familial chylomicronemia in a ...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید
ثبت ناماگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید
ورودعنوان ژورنال:
- The Journal of clinical investigation
دوره 87 4 شماره
صفحات -
تاریخ انتشار 1991