Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:3.1.30.2 (endonuclease)
 18,621 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Digestion of the human apolipoprotein (apo) A-II gene with the endonuclease MspI produces fragments of 3.0 or 3.7 kb, reflecting the presence or absence of a polymorphic site within an Alu sequence 3' to the gene. Patients with hypertriglyceridemia have been shown to have an increased prevalence of the 3.0 kb allele. To explore this observation further, plasma lipoprotein lipids were studied in a random sample of fasted middle-aged Caucasian men, of which 59 were 3.0 kb homozygotes, 24 were heterozygotes, and 2 were 3.7 kb homozygotes. After adjusting for the effects of age, height, weight, alcohol intake and cigarette consumption by covariance analysis, no statistically significant associations were present between genotype and the concentrations of triglyceride in whole plasma or the d less than 1.019 g/ml fraction of plasma (i.e., VLDL + IDL). Nor were the cholesterol concentrations in VLDL + IDL, low density lipoprotein (LDL, d = 1.019-1.063 g/ml), high density lipoprotein (HDL), HDL2 or HDL3 related to genotype. In an independent comparison of eight 3.0 kb homozygotes and eight 3.7 kb homozygotes (all Caucasians) drawn from a different community, genotype was unrelated to the triglyceride or cholesterol concentrations in VLDL (d less than 1.006 g/ml), IDL + LDL (d = 1.006-1.063 g/ml) or HDL, after adjustment for the effects of covariates. These results suggest that the MspI polymorphism of the apo A-II gene is not associated with genetic variation that significantly affects triglyceride transport in the majority of men.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Plasma lipoprotein lipids in relation to the MspI polymorphism of the apolipoprotein AII gene in Caucasian men. Lack of association with plasma triglyceride concentration. 256 9

We report a Canadian kindred with a novel mutation in the apolipoprotein (apo) A-I gene causing analphalipoproteinemia. The 34-yr-old proband, product of a consanguineous marriage, had bilateral retinopathy, bilateral cataracts, spinocerebellar ataxia, and tendon xanthomata. High density lipoprotein cholesterol (HDL-C) was < 0.1 mM and apoA-I was undetectable. Genomic DNA sequencing of the proband's apoA-I gene identified a nonsense mutation at codon [-2], which we designate as Q[-2]X. This mutation causes a loss of endonuclease digestion sites for both BbvI and Fnu4HI. Genotyping identified four additional homozygotes, four heterozygotes, and two unaffected subjects among the first-degree relatives. Q[-2]X homozygosity causes a selective failure to produce any portion of mature apoA-I, resulting in very low plasma level of HDL. Heterozygosity results in approximately half-normal apoA-I and HDL. Gradient gel electrophoresis and differential electroimmunodiffusion assay revealed that the HDL particles of the homozygotes had peak Stokes diameter of 7.9 nm and contained apoA-II without apoA-I (Lp-AII). Heterozygotes had an additional fraction of HDL3-like particles. Two of the proband's affected sisters had documented premature coronary heart disease. This kindred, the third reported apoA-I gene mutation causing isolated complete apoA-I deficiency, appears to be at significantly increased risk for atherosclerosis.
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PMID:Apolipoprotein A-I Q[-2]X causing isolated apolipoprotein A-I deficiency in a family with analphalipoproteinemia. 828 91