Cystathionine Beta-Synthase Deficiency Heralded by Cerebral Sinus Venous Thrombosis and Stroke

BackgroundElevated plasma homocysteine is a risk factor for arterial and venous thromboses in adults. Homocysteine is increased in cystathionine beta-synthase deficiency, a treatable amino acid metabolic disorder that may be missed on newborn screening placing children at risk of thrombosis and strokes.PatientWe present a 3-year-old girl with normal newborn screening for cystathionine beta-synthase deficiency who developed a symptomatic cerebral venous sinus thrombosis. Subsequent testing revealed marked hyperhomocystinemia and genetic testing confirmed cystathionine beta-synthase deficiency.ConclusionsCurrent newborn screening is limited in its ability to detect cystathionine beta-synthase deficiency and although postanalytical interpretation may provide increased sensitivity, a normal newborn screening result should not replace the importance of physician surveillance.