What is the prevalence of homocystinuria and homocysteinemia?

Updated: Jul 27, 2018
  • Author: Pitchaiah Mandava, MD, PhD; Chief Editor: Helmi L Lutsep, MD  more...
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The incidence of homocystinuria in the United States is approximately 1 per 100,000. Internationally, the reported incidence of homocystinuria varies between 1 in 50,000 and 1 in 200,000.

Early diagnosis and intervention have helped in preventing some of the complications of homocystinuria, including ectopia lentis, mental retardation, and thromboembolic events. A mortality rate of 18% by age 30 has been reported by Mudd et al from a worldwide series of 629 patients with CBS enzyme deficiency. [4] Death is predominantly due to cerebrovascular or cardiovascular causes.

Children with CBS deficiency (homocystinuria I) may be normal at birth. Data from Mudd et al suggest that starting at around age 20 years, these patients have an increasing likelihood of suffering a thromboembolic event. Patients with either defective methylcobalamin synthesis or defective tetrahydrofolate metabolism may present in early infancy.

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