Functional analysis of LDLR promoter and 5' UTR mutations in subjects with clinical diagnosis of familial hypercholesterolemia.

Familial hypercholesterolemia (FH) is a dominant disorder due to mutations in the LDLR gene. Several mutations in the LDLR promoter are associated with FH. Screening of 3,705 Spanish FH patients identified 10 variants in the promoter and 5' UTR. Here, we analyse the functionality of six newly identified LDLR variants. Mutations located in the LDLR promoter regulatory elements R2 and R3 (c.-155_-150delACCCCinsTTCTGCAAACTCCTCCC, c.-136C>G, c.-140C>G, and c.-140C>T) resulted in 6 to 15% residual activity in reporter expression experiments and changes in nuclear protein binding affinity compared to wild type. No reduction was observed when cells were transfected with c.-208T, c.-88A, and c.-36G mutant fragments. Our results indicate that mutations localized in R2 and R3 are associated with hypercholesterolemia, whereas mutations outside the LDLR response elements are not a cause of FH. This data emphasizes the importance of functional analysis of variants in the LDLR promoter to determine their association with the FH phenotype.

[Epidemiology of cerebrovascular disease in Spain]. / Epidemiología de la enfermedad vascular cerebral en España.

In Spain, cerebrovascular disease (CVD) is a very common cause of morbidity and hospitalization. They are the second leading cause of mortality in the general population, and the first in women. They also constitute a very high social spending, which is estimated to increase in coming years, due to the aging of our population. Data from the Hospital Morbidity Survey of the National Statistics Institute recorded, in 2011, 116,017 strokes and 14,933 transient ischemic attacks, corresponding, respectively, to an incidence of 252 and 32 events per 100,000 people. In 2002, the cost of hospitalization for each stroke was estimated at €3,047. The amount of total cost health care throughout the life of a stroke patient is calculated at €43,129. Internationally, the direct costs of stroke constitute 3% of national health spending, this being similar amount in different countries around us. Hypertension was the cardiovascular risk factor (CVRF) more prevalent in both ischemic and hemorrhagic strokes, followed by dyslipidemia and diabetes mellitus. Peripheral arterial disease and hypertension were more frequently associated with atherothrombotic events, atrial fibrillation with cardioembolic strokes, and obesity and high blood pressure to lacunar infarcts. In Spain, as showing several studies, we are far from optimal control of CVRF, especially in secondary prevention of stroke. According to the ICTUSCARE study, achieving recommended values was 17.6% in the case of hypertension, 29.8% in LDL-cholesterol, 74.9% of smoking, and 50.2% in diabetes mellitus. In this review, we analyze in detail the epidemiology, prevention and costs originated by CVD.

Screening of APOB gene mutations in subjects with clinical diagnosis of familial hypercholesterolemia.

Monogenic hypercholesterolemia is a group of lipid disorders, most of which have autosomal dominant transmission. Familial defective apoB (FDB) resulting from mutations in the APOB gene is a well-recognized cause of autosomal dominant monogenic hypercholesterolemia (ADMH). However, the frequency of FDB among patients with ADMH is not well established. The aim of our research was to screen for mutations responsible for FDB in subjects with a clinical diagnosis of familial hypercholesterolemia. We studied 408 patients from the Spanish Register of Familial Hypercholesterolemia, proportionally distributed among all Spanish regions. Abnormal SSCP patterns of the APOB gene were checked by DNA sequencing and restriction analysis. Three out of the 408 patients were carriers of the R3500Q mutation, and 2 subjects were carriers of the silent T3552T mutation; in both of these patients functional mutations in the LDL receptor gene were found. We conclude that FDB is not a common cause of ADMH in Spain; the R3500Q mutation is the only mutation in APOB causing FDB, and the LDL receptor binding domain of APOB is highly conserved in the studied sample.