Founder mutations in the Netherlands: geographical distribution of the most prevalent mutations in the low-density lipoprotein receptor and apolipoprotein B genes.

BACKGROUND: In the Netherlands, a screening programme was set up in 1994 in order to identify all patients with familial hypercholesterolaemia (FH). After 15 years of screening, we evaluated the geographical distribution, possible founder effects and clinical phenotype of the 12 most prevalent FH gene mutations. METHODS: Patients who carried one of the 12 most prevalent mutations, index cases and those identified between 1994 and 2009 through the screening programme and whose postal code was known were included in the study. Low-density lipoprotein cholesterol (LDL-C) levels at the time of screening were retrieved. The prevalence of identified FH patients in each postal code area was calculated and visualised in different maps. RESULTS: A total of 10,889 patients were included in the study. Mean untreated LDL-C levels ranged from 4.4 to 6.4 mmol/l. For almost all mutations, a region of high prevalence could be observed. In total, 51 homozygous patients were identified in the Netherlands, of which 13 true homozygous for one of the 12 most prevalent mutations. The majority of them were living in high-prevalence areas for that specific mutation. CONCLUSIONS: Phenotypes with regard to LDL-C levels varied between the 12 most prevalent FH mutations. For most of these mutations, a founder effect was observed. Our observations can have implications with regard to the efficiency of molecular screening and physician's perception of FH and to the understanding of the prevalence and distribution of homozygous patients in the Netherlands.

Magnesium pyridoxal-5'-phosphate glutamate, "A vitamin B6 derivative", does not affect lipoprotein levels in patients with familial hypercholesterolaemia.

OBJECTIVE: In this double-blind, randomized, placebo-controlled, dose-finding study we assessed the short-term efficacy and safety of increasing dosages of magnesium pyridoxal-5'-phosphate glutamate (MPPG) compared to placebo in patients with familial hypercholesterolaemia (FH). Twenty-three patients of either sex, over the age of 18 years and suffering from heterozygous FH, were treated with MPPG for a period of 16 weeks. RESULTS: Baseline characteristics and lipoprotein profiles of the patients were comparable in the two treatment groups. Overall compliance was 90%. Neither after the first 8 weeks treatment period with 450 mg MPPG daily nor after the second 8 weeks treatment period with 600 mg MPPG daily were statistically significant changes in plasma total cholesterol, low-density lipoprotein (LDL) cholesterol, high-density lipoprotein (HDL) cholesterol or triglyceride levels observed between the treatment and placebo groups. Plasma levels of lipoprotein (Lp)(a), apolipoprotein (apo) A1, apo B100, very low density lipoprotein (VLDL) cholesterol and VLDL triglyceride also did not change. CONCLUSION: Although it has been demonstrated that MPPG improves lipoprotein levels in patients with different forms of dyslipidaemia, MPPG is not effective for the treatment of FH patients.

Systemic coagulation and fibrinolysis in patients with or at risk for the adult respiratory distress syndrome.

The authors sought to evaluate the pathogenetic and prognostic role of a procoagulant and hypofibrinolytic state in the adult respiratory distress syndrome (ARDS). Twenty-two consecutive patients admitted to the intensive care unit (ICU) for respiratory monitoring (n = 2) or mechanical ventilation (n = 20) were studied, of whom 13 had ARDS and 9 were at risk for the syndrome. Plasma levels of thrombin-antithrombin III complexes (TAT), the plasmin-alpha2-antiplasmin complexes (PAP), tissue-type plasminogen activator (tPA) and plasminogen activator inhibitor type 1 (PAI-1) were measured within 48 h after admission, together with respiratory variables allowing computation of the lung injury score (LIS), and pulmonary microvascular permeability [67Gallium-transferrin pulmonary leak index (PLI)], as measures of pulmonary dysfunction. Blood was also sampled 6-hourly until 2 days after admission. The LIS and PLI were higher in ARDS than at risk patients, in the presence of similar systemic morbidity and mortality. TAT complexes were elevated in a minority of patients of both groups, whereas the PAP, tPA and PAI levels were elevated above normal in the majority of ARDS and at risk patients, but groups did not differ. Neither circulating coagulation nor fibrinolysis variables correlated to either LIS or PLI. Furthermore, the course of haemostatic variables did not relate to outcome. These data indicate that systemic activation of coagulation and impaired fibrinolysis do not play a major role in ARDS development and outcome in patients with acute lung injury.

Frequency of pregnancy-related venous thromboembolism in anticoagulant factor-deficient women: implications for prophylaxis.

BACKGROUND: It has been reported that women with an inherited deficiency of antithrombin, protein C, or protein S have an increased risk for developing venous thromboembolic disease during pregnancy and the postpartum period. However, because the available data on risk are flawed, it is difficult to define a rational, efficacious, and safe policy about prophylaxis for venous thromboembolism in these women. OBJECTIVE: To determine the frequency of venous thromboembolism during pregnancy and the postpartum period in women with heritable deficiencies of anticoagulant factors. DESIGN: Retrospective cohort study. SETTING: University outpatient clinics in the Netherlands and Italy. PARTICIPANTS: 129 otherwise asymptomatic female family members of patients with a history of venous thromboembolism and an established deficiency of antithrombin, protein C, or protein S. MEASUREMENTS: Medical history, with specific attention to episodes of venous thromboembolism and obstetric history, was taken. The anticoagulant factor status of the study participants was determined. If a patient had an episode of venous thromboembolism, subsequent pregnancies in that patient were not analyzed. RESULTS: Of the 129 women who participated in the study, 60 had anticoagulant factor deficiency and 69 did not. In the nondeficient group, 198 pregnancies occurred; 1 of these (0.5%) was complicated by an episode of venous thromboembolism during the postpartum period. In the deficient group, 169 pregnancies occurred; 7 of these (4.1%) were complicated by an episode of venous thromboembolism during the third trimester of pregnancy (2 pregnancies [1.2%]) and the postpartum period (5 pregnancies [3.0%]). The risk for venous thromboembolism was increased eightfold in deficient women compared with nondeficient women (hazard ratio, 8.0 [95% CI 1.2 to 184]). CONCLUSIONS: Anticoagulant factor-deficient women have an increased risk for venous thromboembolism during pregnancy and the postpartum period. Although data from an appropriate randomized clinical trial are lacking, the frequency of venous thromboembolism seen in deficient women might justify the use of anticoagulative prophylaxis during the third trimester of pregnancy and the postpartum period.