Newborn screening for homocystinuria

Review question

We reviewed the evidence to determine if newborn population screening for the diagnosis of homocystinuria due to cystathionine beta synthase deficiency leads to clinical improvement compared to later clinical diagnosis and to determine the psychological effects on parents or carers of newborn population screening for homocystinuria. This is an update of a previously published review.

Background

Homocystinuria is a rare condition caused by mistakes in a gene that is responsible for making an enzyme called cystathionine beta synthase. People with homocystinuria have a deficiency of this enzyme and as a result have high levels of a substance called homocysteine in their bodies. Although such individuals appear normal at birth, over a period of months and years, they develop serious problems that effect eyesight, lead to delayed mental development, cause unhealthy bones, and have a high risk of having blood clots. Treatment with a special diet and medicines can prevent the development of these complications, but must be started very early in life to be truly effective. In some parts of the world homocystinuria has been tested for in newborn babies.

Search date

The evidence is current to: 08 June 2015.

Key results

No trials were found. We know of some uncontrolled studies which suggest that newborn screening for homocystinuria and its early treatment are effective. Future long-term research is needed to provide strong evidence for or against screening. This research may also show whether screening is cost effective.

Authors' conclusions: 

We were unable to identify eligible studies for inclusion in this review and hence it is not possible to draw any conclusions based on controlled studies; however, we are aware of uncontrolled case-series which support the efficacy of newborn screening for homocystinuria and its early treatment. Any future randomised controlled trial would need to be both multicentre and long term in order to provide robust evidence for or against screening and to allow a cost effectiveness analysis to be undertaken.

Read the full abstract...
Background: 

Homocystinuria is a rare inherited disorder due to a deficiency in cystathionine beta synthase. Individuals with this condition appear normal at birth but develop serious complications in childhood. Diagnosis and treatment started sufficiently early in life can effectively prevent or reduce the severity of these complications. This is an update of a previously published review.

Objectives: 

To determine if newborn population screening for the diagnosis of homocystinuria due to cystathionine beta synthase deficiency leads to clinical benefit compared to later clinical diagnosis.

Search strategy: 

We searched the Cochrane Cystic Fibrosis and Genetic Disorders Group's Inborn Errors of Metabolism Trials Register.

Date of the most recent search of the Inborn Errors of Metabolism Register: 08 June 2015.

Selection criteria: 

Randomised controlled trials and controlled clinical trials assessing the use of any neonatal screening test to diagnose infants with homocystinuria before the condition becomes clinically evident. Eligible studies compare a screened population versus a non-screened population.

Data collection and analysis: 

No studies were identified for inclusion in the review.

Main results: 

No studies were identified for inclusion in the review.

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