<n0:ComplexDefinition xmlns:n0="http://ncicb.nci.nih.gov/xml/owl/EVS/ComplexProperties.xsd#"><n0:def-definition>A serious metabolic condition caused by mutations in the MTHFR gene, medications, or nutritional deficiency. It results in increased levels of homocysteine in the blood. Patients with this condition are at an increased risk for recurrent blood clots formation and cardiovascular accidents.</n0:def-definition><n0:def-source>NCI</n0:def-source></n0:ComplexDefinition>