Glossary of Terms

Click on a word/phrase below to see its definition.

DNA

DNA

The genetic language. It is contained within the cell’s nucleus in the form of chromosomes. The DNA alphabet is made up of 4 different nucleotides, adenine, guanine, thymine and cytosine, abbreviated AGTC. The genetic language is “read” in triplets so AGT, CTA (much like you read off your credit card number in sets of four, DNA is sets of three). These codons or sets of three are first transcribed into RNA and then encode a particular amino acid that when put next to another amino acid forms a particular protein. Some sets of three represent stop signs or pauses in the reading frame. Sometimes a mutation (or change) in one letter of the DNA alphabet creates a stop sign where an amino acid should be coded. This is one example of a mutation called a nonsense mutation.

Dominant Negative

Dominant Negative

This describes the mechanism by which a dominant mutation can cause disease. A mutation whose gene product adversely affects the normal (wild type) gene product within the same cell. The mutated copy may associate with the normal copy and cause dysfunction of both. In some cases, such as collagen (Ullrich CMD), one dominant negative mutation may be more harmful than having one mutation causing the production of no gene product (null mutation or null alleles), which only cause disease when present in both gene copies so that absolutely no product can be made.

Doxycycline

Doxycycline

A drug currently being tested to slow apoptosis (muscle cell death)

Duplication Analysis

Duplication Analysis

Molecular genetic testing to identify larger size deletions or duplications (typically between 40 basepairs and 40 Kilobases) of DNA within a gene. These methods typically do not detect smaller deletions or duplications of a few base pairs (which can be identified by other methods). Methods used include: array CGH; Multiplex Ligation-dependent Probe Amplification (MLPA); quantitative, real-time, or deletion-specific PCR; or Southern blot.

Dysmobility

Dysmobility

When digested food does not move through the stomach or intestines at the right speed. Digested food moves through our body when the muscles in our intestines move like a wave to push the food along. Sometimes the wave moves too slowly and can cause constipation. Other times it moves too quickly and can cause diarrhea.

Dystrophin

Dystrophin

Dystrophin, or DMD, is the largets known human gene and provides instructions for making a protein called dystropohin. The protein is located primarily in muscles used for movement (skeletal muscles) and in the heart (caridac muscles). Small amounts of dystrophin are present in nerve cells in the brain.

Dystrophy

Dystrophy

The degeneration and replacement of muscle tissue by fatty cells or fibrosis.

Eccentric Exercise

Eccentric Exercise

The lengthending of muscle while producing force, usually by returning from a shortened (concentric) position to a resting position. Using the same example above, the lowering the weight back down during a biceps curl.

Echocardiogram

Echocardiogram

An ultrasound image of the heart that demonstrates the size, motion, and composition of cardiac structures

EDMD/Emery Dreifuss Muscular Dystrophy

EDMD/Emery Dreifuss Muscular Dystrophy

The CMD Subtype cause by genetic defects in the Emerin, LMNA, or FHL1 gene that causes muscle weakness and cardiac dysfunction.

EHR

EHR

Electronic Health Record.

Ejection Fraction

Ejection Fraction

As measured during an echocardiogram, the blood present in the ventricle at the end of diastole and expelled during contraction of the heart.

 

Electrocardiogram (EKG/ECG)

Electrocardiogram (EKG/ECG)

An electrocardiogram (EKG or ECG) is a test that checks for problems with the electrical activity of your heart, showing the heart's electical activity as line tracing on paper; the spikes and dips in the tracings are called waves.

EMA

EMA

European Medicines Agency, a federal agency responsible for approving the trial and use of drugs and other interventions in the European Union

Emerin

Emerin

Emerin is a protein that in humans is encoded by the EMD gene, also known as the STA gene. Emerin, together with LEMD3, is a LEM domain-containing integral protein of the inner nuclear membrane in vertebrates.