This glossary will help you to understand some of the terminology used when we talk about Duchenne muscular dystrophy research.
A type of virus which is used as a vector in gene therapy: a system for delivering treatments such as microdystrophin.
The structural units that make up proteins in living things.
A biomarker is anything in the body that can be used to measure the state of the body. Biomarkers can be found in blood, urine or saliva. In clinical trials they can be used to measure whether a drug is having an effect.
Removing a sample of tissue (such as muscle) from the body so the tissue can examined. This may be to understand more about the state of the muscle. Biopsies are used in clinical trials to examine the muscle and look at whether treatments may be having an effect.
Anything to do with the heart.
Cardiomyopathy is a disease of the heart muscle that makes it harder for your heart to pump blood to the rest of your body. Cardiomyopathy can lead to heart failure.
A carrier is a woman who has the faulty DMD gene, but who does not have the symptoms, or only has them mildly. This is because the DMD gene is located on a chromosome called the X chromosome. Boys have one X chromosome and one Y chromosome; girls have two X chromosomes, so if there is a problem with the DMD gene on one of the X chromosomes, the other can compensate for it.
The smallest structural units of living matter that all living things are composed of.
Long strings of genetic material made up of DNA and accessory proteins. The DNA contains approximately 30,000 to 100,000 genes that make up the human genome. Chromosomes come in pairs, and a normal human cell contains 46 chromosomes, 22 pairs of autosomes and two sex chromosomes.
Stage 1: Determining which dose is safe, how often if should be given and the best form of treatment. Few participants.
Stage 2: Assessing the effectiveness of the treatment, its side effects and tolerance levels. More participants.
Stage 3: Determining whether the new treatment works better than an alternative current standard treatment.
A treatment in which a patient is given two or more drugs (or other therapeutic agents) for a single disease.
Short for deoxyribonucleic acid. A very long molecule that carries a cell’s genetic information. DNA is in each cell of all living things.
A protein found in skeletal muscle, which people with DMD are unable to create. Dystrophin is one of a group of proteins that work together to strengthen muscles and protect them from injury.
A protein that accelerates a specific chemical reaction in a cell.
A technique where living tissues are taken directly from a living organism, rather than created artificially, and testing is carried out on them with very minimal changes to the tissue’s natural state. ‘Ex vivo’ means ‘outside of a living body’ in Latin.
This varies slightly to ‘in vitro’ testing, where cells are separated from their natural environment and experiments are carried out in very controlled environments.
The active part of the dystrophin gene is made up of 79 pieces called exons. These exons link together to form a code that is read in the cells so that the protein dystrophin can be made.
In DMD, some of the exons are not readable. The consequence is that very little or no dystrophin is made.
Exon skipping is a DMD treatment which causes cells to “skip” over faulty or misaligned sections of genetic code, leading to a shortened, but still functional protein.
The formation of bands of fibrous tissue, called scar tissue, between muscle fibres. A build-up makes it difficult for the muscle to contract and relax normally.
A segment of DNA found on a chromosome that codes for a particular protein. Humans have approximately 20-25,000 genes.
The total loss or absence of a gene.
The amount of protein created by the gene.
Determining the relative positions of genes on a chromosome and the distance between them.
Examining a sample of blood or other body fluid or tissue for biochemical, chromosomal, or genetic markers that indicate the presence or absence of genetic disease.
Gene therapy is a treatment that aims to treat a genetic disease by repairing the damaged gene responsible for the disease. It involves introducing a normal copy of the gene into cells containing the damaged version.
The sum of all the genetic material in the chromosomes of a particular organism.
The actual genes carried by an individual.
A state in which the immune system’s ability to fight infectious disease is compromised or entirely absent. Most cases of immunodeficiency develop over time (“secondary”) but some people are born with defects in the immune system (“primary”).
A medical test, experiment, or procedure that is done on (or in) a living organism, such as a laboratory animal or human.
A medical test or experiment that uses biological components such as cells or biological molecules and is carried out outside of a living organism, such as in a test tube or petri dish. ‘In vitro’ means ‘in glass’ in Latin.
A part of the body’s natural reaction to infection or trauma. It occurs in muscle cells after they have been damaged and is a result of the lack of dystrophin. The prevention of inflammation is important in stopping the progression of DMD.
A frequently used animal model for studying Duchenne muscular dystrophy. This is a mouse which has a mutation in its DMD gene, like humans with DMD.
A group of atoms arranged to interact in a particular way; one molecule of any substance is the smallest physical unit of that particular substance .
A type of scan that uses strong magnetic fields and radio waves to produce detailed images of the inside of the body.
A group of inherited diseases that damage and weaken your muscles over time. Duchenne is one type of muscular dystrophy, but there are nine major forms of MD.
The changing of the structure of a gene. This is caused by the deletion, insertion, or rearrangement of larger sections of genes or chromosomes.
The usual course or development of a disease or condition, especially in the absence of treatment. A natural history study collects health information in order to understand how the medical condition or disease develops and how to treat it.
A round part of a cell that contains the chromosomes and controls the activities of the cell.
A type of genetic mutation that causes mRNA to prematurely stop reading DNA code, resulting in a shorter version of the protein being produced.
The standard set of functional test to measure disease progression in Duchenne muscular dystrophy.
A substance that has no therapeutic effect. Placebos are used as a control in testing new drugs, to see if the drug being tested is having an effect.
How the disease progresses in an individual patient.
Antibodies are a type of protein which the immune system uses to protect the body from foreign invaders, such as viruses. Current gene therapy trials use a type of virus called Adeno-Associated viruses (AAVs) to deliver the therapy. However, some patients already have antibodies against these viruses, which prevents the therapy from reaching their body.
Proteins are essential to the structure, function, and regulation of the body. Examples are hormones, enzymes, and antibodies.
Using a drug that is already an approved treatment for one disease as a treatment for another disease.
A molecule that is chemically similar to DNA and carries the same code. The several classes of RNA molecules play important roles in protein synthesis and other cell activities.
An adverse event is when a patient experiences an undesirable side effect associated with the use of a medical product. The event is considered serious if it results in death, hospitalisation or prolongation of existing hospitalisation, persistent or significant disability/incapacity or a congenital anomaly or birth defect.
A test to measure how far a patient can walk for 6 minutes, commonly used as a measure in DMD clinical trials.
Stem cells are special human cells that have the ability to develop into many different cell types, from muscle cells to brain cells.
A sex chromosome. Females carry two X chromosomes.
A sex chromosome. Males carry one Y and one X chromosome.