Diagnosis
Diagnosis often can be made through clinical examination and urine tests (excess mucopolysaccharides are excreted in the urine). Enzyme assays (testing a variety of cells or body fluids in culture for enzyme deficiency) are also used to provide definitive diagnosis of one of the mucopolysaccharidoses. Prenatal diagnosis using amniocentesis and chorionic villus sampling can verify if a fetus either carries a copy of the defective gene or is affected with the disorder. Genetic counseling can help parents who have a family history of the mucopolysaccharidoses determine if they are carrying the mutated gene that causes the disorders. Types
Seven distinct clinical types and numerous subtypes of the mucopolysaccharidoses have been identified. Although each mucopolysaccharidosis (MPS) differs clinically, most patients generally experience a period of normal development followed by a decline in physical and/or mental function. (Note: MPS-V and MPS-VIII are no longer in use as designations for any disease.) Overview table
MPS I
MPS I is divided into three subtypes based on severity of symptoms. All three types result from an absence of, or insufficient levels of, the enzyme alpha-L-iduronidase. Children born to an MPS I parent carry the defective gene. MPS I H (also called Hurler syndrome or α-L-iduronidase deficiency), is the most severe of the MPS I subtypes. Developmental delay is evident by the end of the first year, and patients usually stop developing between ages 2 and 4. This is followed by progressive mental decline and loss of physical skills. Language may be limited due to hearing loss and an enlarged tongue.
The most common side effects with vonicog alfa (which may affect up to 1 in 10 patients) are dizziness, vertigo (a spinning sensation), dysgeusia (taste disturbances), tremor, rapid heartbeat, deep venous thrombosis (blood clot in a deep vein, usually in the leg), hypertension (high blood pressure), hot flush, vomiting, nausea (feeling sick), pruritus (itching), chest discomfort, sensations like numbness, tingling, pins and needles at the site of infusion, and an abnormal reading on the electrocardiogram (ECG). References
Further reading
AusPAR: Vonicog alfa. Therapeutic Goods Administration (TGA) (Report). October 2020. External links
"Vonicog alfa". Drug Information Portal. U.S. National Library of Medicine.