Snapshot A fair skinned, blue eyes, developmentally delayed 5 year-old child is brought to the ER. He has a medical history showing failure to thrive and developmental delay. According to the mother the child developed a seizure disorder after he had a thrombolic episode involving the brain Introduction Results from abnormalities in the cysteine metabolism ETiology Genetics login to view 3 more bullets Presentation Infants are normal at birth but soon show login to view 2 more bullets Symptoms mimic Marfan's Syndrome login to view 10 more bullets studies Serum blood testing demonstrating increased levels of methionine and homocysteine Genetic testing can be performed but is much more costly Treatment Some patients respond to treatment with vitamin B6 complications Thromboembolic events are more common in homocysteinuria than in the common population