Association between MTHFR C677T polymorphism and congenital heart disease. A family-based meta-analysis.

Congenital heart disease (CHD) is the most common type of birth defect. It is suspected that polymorphisms in folate metabolism are associated with an increased risk of CHD, but the conclusion remains unclear. Studies have reported that the MTHFR C677T polymorphism was associated with the development of structural congenital heart malformations. The objective of this study was to conduct a meta-analysis of available studies to identify common polymorphisms in the MTHFR gene in children with CHD and their mothers and to test for an association between genotype and disease. In all, 19 eligible studies comprising 4,219 cases and 20,123 controls were included in this meta-analysis. A significant association was found between the MTHFR C677T polymorphism and CHD risk (OR: 1.26; 95 % CI = 1.06-1.51; p = 0.009) with no strong evidence of heterogeneity (I(2) = 39 %) in the fetal analysis. In the maternal analysis, the MTHFR C677T polymorphism was significantly associated with CHD risk (OR = 1.52; 95 % CI = 1.09-2.11; p = 0.01) with significant heterogeneity (I(2) = 63 %).

Suspected deep vein thrombosis. Management by impedance plethysmography.

Controversy exists as to whether patients suspected of having deep vein thrombosis (DVT) can be studied safely without venography, with its attendant expense, inconvenience, and potential risk. We used impedance plethysmography (IPG) in 1,464 consecutive patients suspected of having DVT, with 96% of these patients with normal IPGs, there were no fatal pulmonary emboli (PE). The incidence of nonfatal PE was 1%. In 284 outpatients suspected of having DVT, but discharged without treatment because of normal IPGs, only one patient returned with subsequent symptoms of DVT (0.4%). Noninvasive testing with IPG is a safe and highly cost-effective alternative to venography for routine management of patients suspected of DVT.