Glossary
Autosomal Dominant:
A genetic condition that appears in an affected individual who has one copy of a faulty or disease causing gene, as well as one normal gene.
Autosomal Recessive:
A genetic condition that appears in an affected individual who has two copies of a faulty or disease causing gene.
Carrier:
A carrier is someone who does not have a disease, but has one copy of a faulty, autosomal recessive disease-causing gene and one normal copy. Both parents must be carriers of the same faulty gene to produce a child who has the disease.
Clinical Trial:
A clinical trial is a research study in human volunteers to answer specific health questions.
Cofactor:
Substances in the body that help enzymes function.
Corneal clouding:
The clear layers of the cornea in the eye become cloudy due to the build up of GAG in the eye. It may make it difficult to see in dim or very bright light.
Diaphragm:
A sheet of internal muscle that extends across the bottom of the rib cage.
DNA (deoxyribonucleic acid):
Genetic material in cells that holds the inherited instructions for growth, development, and cellular functioning.
Dose finding:
Using different doses of study drug to determine which dose works the best and is the safest.
Double Blind:
Neither the patient or the doctor or study team members knows who is receiving the study drug or the placebo.
Efficacy study:
Studies to determine if the study drug works.
Enzyme:
Proteins in the body that produce a chemical action.
Enzyme replacement therapy (ERT):
Medical treatment to replace an enzyme in patients in whom that particular enzyme is absent or deficient. It is usually given as an intravenous infusion. There are currently approved ERTs for six lysosomal storage disorders, including ERTs for MPS I and MPS VI.
Genetic disease:
A disease caused by abnormalities in genes or chromosomes.
Glycosaminoglycans (GAG):
Long chains of sugar molecules used in the building of bones, cartilage, skin, tendons and many other tissues in the body. They are continually made and broken down in the lysosome in the cell. In various MPS diseases, the body lacks the specific enzymes necessary to break down GAG. The accumulated GAG in the body leads to the symptoms associated with MPS diseases.
Incidence:
The frequency of new cases of a disease or condition in a population.
Keratan sulfate (KS):
A GAG that patients with MPS IVA are unable to break down due to missing enzyme. The keratan sulfate remains stored in the cells and leads to progressive damage.
Lysosomal storage disorders:
Disorders caused by deficiency of specific lysosomal enzymes that normally degrade glycoproteins, glycolipids, or mucopolysaccharides.
Lysosome:
An organelle inside cells that is part of the intracellular digestive system. GAG that is not broken down or recycled as normal builds up in lysosomes resulting in disease symptoms.
Mucopolysaccharidosis (MPS):
A group of metabolic disorders caused by the absence or malfunctioning of lysosomal enzymes needed to break down molecules called glycosaminoglycans.
Mucopolysaccharides:
Original name given to chains of sugar molecules used in the building of bones, cartilage, skin, tendons, and many other tissues in the body. They are now commonly referred to as glycosaminoglycans.
Mutation:
A change in a gene that could potentially be transmitted to offspring.
Neurocognitive:
Functions associated with areas of the brain.
Open label:
Study that does not contain a placebo. Everyone in the study receives the study drug.
Orphan drug:
An FDA category that refers to medications used to treat rare diseases and conditions.
Pharmacodynamics:
The impact of the drug on selected tissues of the body.
Pharmacokinetics:
Studies that look at where the study drug is distributed in the body and the length of time that it takes the body to use the study drug and to eliminate it as waste.
Placebo / Placebo controlled:
A preparation that looks like the study drug, but does not contain any of the active study drug. Placebo controlled is a study that has some patients receiving study drug and some patients receiving placebo, so that it eliminates the power of suggestion in the study results.
Randomized:
Placed into a group by chance like flipping a coin or rolling dice.
Subcutaneous:
Under the skin
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