Launch of One Stop Shop for Diagnosis and Monitoring of Pompe Patients


Scientists in Chemical Pathology at Great Ormond Street Hospital (GOSH), in conjunction with the UCL Institute of Child Health, have now established a fully comprehensive diagnostic and monitoring service for Pompe disease.

Pompe disease is an inherited metabolic disorder (enzyme deficiency) that affects the ability of cells to degrade glycogen via the lysosome.  There is a treatment for this condition in the form of enzyme replacement therapy (ERT).  However, to maximise the efficacy of this treatment, early diagnosis is essential.  Subsequently, patients need to be reliably monitored in case their ERT needs to be modified.

Diagnosis is achieved via enzymatic analysis on dried blood spots.  Spots can be sent into our laboratory from all over the UK and beyond.  A critical follow up test that influences treatment is called CRIM status.  This test evaluates whether a patient has any enzyme protein, albeit non functional, in their body.  If they do, then it may be less likely that they will mount an immune response to their ERT.  If they do not have any protein, then it may be necessary to provide immunosuppressant drugs along with their ERT.  Until now, this test was only available on cultured skin cells that took 6 weeks to grow.  Following this the cells had to be sent to the USA for the test to be performed meaning that there were considerable delays before a child's treatment could be optimised.  Now we can provide this test here at GOSH on a blood sample and provide a result within a week.

Monitoring how well an individual child responds to their ERT is the final part of our service.  We have now developed a method that can monitor the levels of a particular sugar (glucose tetrasaccharide) in the urine of Pompe patients.  This biomarker decreases upon commencement of ERT and may provide a useful indicator for Doctors as to how well the ERT is working.   Until now this test was only available in the USA.

© 2011 Great Ormond Street Hospital for Children NHS Trust