Large-Scale Screening for Monogenic and Clinically Defined Familial Hypercholesterolemia in Iceland

Objective: Familial hypercholesterolemia (FH) is traditionally defined as a monogenic disease characterized by severely elevated LDL-C (low-density lipoprotein cholesterol) levels. In practice, FH is commonly a clinical diagnosis without confirmation of a causative mutation. In this study, we sought to characterize and compare monogenic and clinically defined FH in a large sample of Icelanders. Approach and Results: We whole-genome sequenced 49 962 Icelanders and imputed the identified variants into an overall sample of 166 281 chip-genotyped Icelanders. We identified 20 FH mutations in LDLR, APOB, and PCSK9 with combined prevalence of 1 in 836. Monogenic FH was associated with severely elevated LDL-C levels and increased risk of premature coronary disease, aortic valve stenosis, and high burden of coronary atherosclerosis. We used a modified version of the Dutch Lipid Clinic Network criteria to screen for the clinical FH phenotype among living adult participants (N=79 058). Clinical FH was found in 2.2% of participants, of whom only 5.2% had monogenic FH. Mutation-negative clinical FH has a strong polygenic basis. Both individuals with monogenic FH and individuals with mutation-negative clinical FH were markedly undertreated with cholesterol-lowering medications and only a minority attained an LDL-C target of <2.6 mmol/L (<100 mg/dL; 11.0% and 24.9%, respectively) or <1.8 mmol/L (<70 mg/dL; 0.0% and 5.2%, respectively), as recommended for primary prevention by European Society of Cardiology/European Atherosclerosis Society cholesterol guidelines. Conclusions: Clinically defined FH is a relatively common phenotype that is explained by monogenic FH in only a minority of cases. Both monogenic and clinical FH confer high cardiovascular risk but are markedly undertreated.

Copper, ceruloplasmin and superoxide dismutase in patients with Alzheimer's disease . a case-control study

The copper-containing enzyme superoxide dismutase (SOD) is a key enzyme in suppressing the amounts of superoxide anion radicals. Ceruloplasmin, the copper-transporting protein in plasma, also possesses an important redox capacity. In this study the levels of copper and ceruloplasmin as well as SOD-activity and ceruloplasmin oxidative activity were analyzed in order to throw some light on possible defects in copper mechanisms in patients diagnosed with Alzheimer's disease (AD). The study included 44 patients with AD and their healthy age- and gender-matched controls. No difference of significance was seen when comparing the copper or ceruloplasmin concentration in plasma of AD patients to that of their paired controls. The SOD activity in red blood cells was significantly lower in the patients than in their controls (p = 0.019). The ceruloplasmin oxidative activity in plasma of Alzheimer's patients was greatly reduced as compared to that of age- and gender-matched controls and the difference was highly significant (p = 0.0005). Ceruloplasmin activity and SOD activity were not found to be intrinsically correlated. It was postulated that reduced oxidative activity of ceruloplasmin in plasma might be either a cause or a consequence of AD and that reduced SOD activity might further add to the oxidative disturbances in AD due to defective ceruloplasmin activity.