An MPS blood test is a laboratory test primarily used as a secondary newborn screening tool for mucopolysaccharidosis (MPS) types I and II, and to assist in the diagnosis and monitoring of patients with MPS types I, II, III, IV, and VI. It analyzes blood samples to detect deficiencies in specific enzymes that are crucial for breaking down complex sugar molecules (glycosaminoglycans, or GAGs). These deficiencies are characteristic of MPS disorders.
Here's a breakdown of what that means:
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Mucopolysaccharidosis (MPS): MPS refers to a group of inherited metabolic disorders caused by the absence or malfunction of specific lysosomal enzymes. These enzymes are responsible for breaking down glycosaminoglycans (GAGs). When these enzymes are deficient, GAGs accumulate in cells, tissues, and organs, leading to various health problems.
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Enzyme Assay: The MPS blood test is typically an enzyme assay, which measures the activity level of specific enzymes in the blood. Low enzyme activity can indicate an MPS disorder.
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Newborn Screening: While not typically a primary newborn screening test, an MPS blood test can be used as a second-tier screen if the initial newborn screening results raise concerns or if there is a family history of MPS.
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Diagnosis and Monitoring: The test aids in confirming a diagnosis of MPS in individuals exhibiting symptoms. It can also be used to monitor the effectiveness of treatment, such as enzyme replacement therapy (ERT) or hematopoietic stem cell transplantation (HSCT).
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MPS Types: While the test can assist in the diagnosis and monitoring of MPS types I, II, III, IV, and VI, it is important to note that each MPS type is associated with a deficiency in a different specific enzyme. Therefore, specialized enzyme assays must be performed to identify the specific MPS type.
In summary, the MPS blood test is a valuable tool for identifying and managing individuals with mucopolysaccharidosis by measuring the activity levels of specific enzymes in the blood, helping in early diagnosis, monitoring disease progression, and assessing the effectiveness of treatments.
