This test detects acid alpha-glucosidase enzyme activity that has been associated Pompe disease.

This test may be appropriate for individuals with a clinical suspicion of Pompe disease and/or individuals with a family history of this condition.

Pompe disease is a glycogen storage disorder characterized by a deficiency of the lysosomal enzyme acid-alpha glucosidase. There are three types of Pompe disease: infantile-onset, non-classic infantile-onset, and late-onset. The infantile-onset is the classic form where symptoms begin a few months after birth. Affected infants present with myopathy, hypotonia, hepatomegaly, and heart defects. They are usually described as “floppy”, have difficulty feeding, and fail to thrive. If left untreated, death from heart failure occurs in the first year of life. Late-onset Pompe disease is defined onset before age 12 months without cardiomyopathy and all individuals with onset after age 12 months. Pompe disease is estimated to affect 1 in 40,000 individuals in the United States and varies among different ethnic groups.

Tandem mass spectrometry analysis can be coupled with liquid chromatography, a technique referred to as LC-MS/MS. In this methodology, chromatography is used to separate analytes of interest prior to measurement by the mass spectrometer. This separation reduces interference from matrix components and can also allow for the measurement of analytes that have the same mass (isobaric species), thereby improving analytical specificity compared to MS/MS.