Diagnosis of IEM

Urine provides information critical to the diagnosis, more than blood, and is obtained noninvasively. JCMI can receive urine samples in a frozen state or dried filter paper via regular air mail or any courier service from anywhere in the world.

In general, metabolic disorders are hard to distinguish through general examination or clinical observation. Therefore it is difficult for someone to identify a specific gene as the cause for a disease. Some believe that genetic testing should be performed in each case for definitive diagnosis. However, if the gene had not any mutation detectable by the standard sequencing, further advanced analysis would be required and the time and cost for diagnosis increase. In some cases, the suspected gene may not be the right one, leading to the prolonged undiagnosed.

Other may think it necessary to perform the assay of a specific enzyme activity through biopsy of the liver. This invasive testing is often even thought to be the first step in screening for a suspected disease.  If the suspected enzyme is not the right one, invasive liver biopsy remains just invasive.

If one believes that all three of genetic testing, enzyme assay, and metabolite testing should be completely performed for every patient for diagnosis, and if the order of these three tests is not carefully assessed, a tremendous amount of time and cost may be wasted for the diagnosis of patients. If the order of testing is not right, some patients wil be kept undiagnosed for a long time.