Glossary | The Marfan Foundation

The Marfan Foundation

Know the signs. Fight for victory.

Glossary

A B C D E F G H I J K L M N O P Q R S T U V W X Y Z

A

Abdomen: The portion of the body from just below the ribs to just above the hip bones.

Amblyopia: An imbalance of vision where one eye sees better than the other. If not corrected, the brain may stop registering vision from the weaker eye.

Aneurysm: A bulging or enlargement of an artery.

Antibiotic: A class of substances that destroy or inhibit the growth of other microorganisms.

Anticoagulant: Drug used to thin the blood and prevent blod clots from forming.

Aorta: The large artery that carries blood from the heart to the rest of the body.

Aortic aneurysm: A bulging or enlargement of the aorta.

Aortic dilation: An enlargement of the aorta.

Aortic dissection: A tear in the inner wall of the aorta. Blood surges through this tear into the middle layer of the aorta causing the middle layer to seperate forming an abnormal second channel (called a false lumen) through which blood can flow.

Aortic root: Base portion of the aorta as it leaves the heart.

Aortic valve: The valve in the heart between the left ventricle and the aorta.

Aortic valve insufficiency or aortic valve regurgitation: Abnormal function of the aortic valve that results in the leaking of blood from the aorta back into the left ventricle of the heart.

Arachnodactyly: Long, thin fingers.

Arterial tortuosity: Twisting or spiraled arteries.

Astigmatism: Blurred vision caused by an irregular curve of either the lens or the cornea.

B

Beals syndrome (CCA): A condition caused by a mutation in a gene that helps build connective tissue called fibrillin-2. Beals syndrome is also known as congenital contractural arachnodactyly, or CCA, which refers to the joint contractures that are key features of the syndrome.

Beta-blockers: A class of drugs widely prescribed to lower blood pressure and regulate heart rhythm.

Bicuspid aortic valve: Aortic valve that only has two flaps instead of the normal three.

C

Cardiologist: A medical doctor who specializes in the heart and aorta.

Chromosome: A structure found in the cell nucleus that contains the genes; chromosomes are composed of DNA and are found as pairs in each cell. Each parent contributes one chromosome to each pair, so every child gets half of his/her chromosomes from the mother and half from the father.

Cleft palate: Opening or gap in the roof of the mouth; can be covered by a mucous membrane called submucous cleft.

Composite graft: A woven cloth tube (often made of Dacron) with a mechanical valve sewn into one end. The tube and valve combination is used to replace the damaged aortic root and aortic valve.

Congenital: Condition existing at birth.

Congenital hip dysplasia: Abnormally developed hip that leaves the hip joint unstable with the possibility of hip dislocation.

Congestive heart failure: A condition which occurs when the heart is unable to circulate blood to the body because it's pumping ability is weakened.

Connective tissue: Helps to hold the body’s cells, organs, and tissues together and also helps to control how the body grows and develops. The “glue” and “scaffolding” of the body.

Contracture: Tightening of muscle, tendons, ligaments, or skin that prevents normal movement.

Craniosynostosis: Early fusion of the skull bones.

D

Diagnosis: Determination of the nature of a disease.

DNA (deoxyribonucleic acid): A molecule used to make genes that tell our body how to grow and develop.

Dominant: A gene on one chromosome which results in a specific condition even though the individual's genetic make-up includes a copy of the gene. With a dominant gene, the chance fo passing on the gene (which may cause a condition or disease) to children is 50-50.

Dural ectasia: The central nervous system – the brain and the spinal cord – are surrounded by fluid contained by a membrane called the dura, which is primarily made up of connective tissue. The enlargement of this membrane is referred to as dural ectasia.

E

Echocardiograph or Echocardiogram: A painless, non-invasive test that uses high frequency sound waves to examine and take pictures of the heart and surrounding tissues.

Ectopia lentis: A dislocated or off-center lens of the eye.

Ehlers-Danlos syndrome: A group of genetic connective tissue disorders characterized by unstable, hypermobile joints, loose, “stretchy” skin, and fragile tissues.

Electrocardiogram (ECG or EKG): Recording of the electrical activity of the heart over time.

Endocarditis: Infection of a lining of the heart cavity and valve.

Endocarditis prophylaxis: The taking of antibiotics to prevent endocarditis prior to any procedure that is likely to release harmful bacteria into the blood stream.

Extracellular matrix: A mixture of proteins, including fibrillin-1, that forms a structure or “scaffolding” outside of the cells of the body that helps keep the cells in place.

F

Familial ectopia lentis: An inherited connective tissue disorder that shares some of the features of Marfan syndrome – particularly dislocation of the lens of the eye, which can cause serious vision problems.

Familial aortic aneurysm and dissection: When a person has a genetic predisposition (meaning it runs in the family) to aortic thoracic aneurysm and dissection.

Fibrillin-1: A protein of the connective tissue.

G

Gene: A specific sequence of DNA located on a chromosome that creates a protein to perform a specific function in the body.

Geneticist: Doctor who diagnoses genetic conditions.

Genotype: The genetic makeup of a cell or individual.

H

Heritable: Capable of being transmitted from parent to child.

Hernia: Protrusion of an organ or body part through a hole in the skin or connective tissue.

Homograft: Human or pig tissue used to replace a damaged aorta and valve.

Homocystinuria: An inherited metabolic disorder that affects the body’s ability to properly process amino acids (the building blocks of proteins). This defect leads to disorders of the connective tissue, muscles, heart and blood vessels, and the central nervous system.

Hypertelorism: Widely spaced eyes.

I

Inherited: Transmitted through genes from parents to offspring.

K

Kyphosis: A curving of the spine front to back. Kyphosis often creates a “hunch back.”

L

Loeys-Dietz syndrome: A genetic disorder of the body’s connective tissue caused by a mutation of either one of the two genes. These genes are called transforming growth factors beta recepter 1 (TGFBR1) and transforming growth factors beta receptor 2 (TGFBR2). When either of these genes has a mutation, growth and development of the body's connective tissue and other body systems is disrupted, leading to the signs and symptoms of Loeys-Dietz syndrome.

M

Magnetic Resonance Imaging (MRI): An imaging technique used to examine and take pictures of internal structures of the body.

Malocclusion: Poor positioning or inappropriate contact between teeth when the mouth is closed.

Marfan habitus: A condition in which a person has the skeletal features of Marfan syndrome but doesn’t have any aortic or eye features.

MASS Phenotype: A connective tissue disorder similar to Marfan syndrome; MASS stands for the Mitral valve, Aorta, Skin and Skeletal features of this disorder.

Microfibril: Tiny microscopic rod-like structures composed of proteins, including fibrillin-1, that form the framework of the elastic fibers in connective tissue.

Mitral regurgitation: The back flow of blood from the left ventricle to the left atrium of the heart through an abnormal mitral valve. Also know as mitral valve incompetence.

Mitral valve: The heart valve between the left atrium and ventricle.

Mutation: A permanent structural change in DNA that can cause a condition.

Myopia: Nearsightedness.

N

Nucleotide: One of the structural components, or building blocks, of DNA and RNA. A nucleotide consists of a base (one of four chemicals: adenine, thymine, guanine, and cytosine) plus a molecule of sugar and one of phsphoric acid.

O

Ophthalmologist: A doctor who specializes in diseases of the eye and ocular nerve.

Orthopedist: A medical doctor who specializes in the bones and joints.

Osteoporosis: Poor mineralization of bones leading to decreased bone mass and fragile bones.

P

Patent ductus arteriosis: Continued opening between the aorta and pulmonary artery which causes oxygenated and unoxygenated blood to mix. May be seen at birth, but should close in infancy.

Pectus carinatum: A breast bone that sticks out, sometimes called “pigeon breast.”

Pectus excavatum: Caved-in, sunken or indented chest, sometimes called “funnel chest.”

Pedigree: A diagrammatic record of genes within families.

Pes planus: A condition where the arch of the foot has flattened out so that the entire sole of the foot rests on the ground. Also known as flat feet.

Phenotype: The traits or characteristics of an organism that can be seen; for example, hair color, weight, or the presence or absence of a disease.

Pneumothorax: Spontaneous collapse of the lung.

Prophylactic: Preventitive measure.

Protein: A molecule made up of a number of amino acids arranged in a specific order. Proteins are essential for all life processes. DNA tells the cell how to make proteins.

Protrosio acetabulae: Severe deepening of the hip socket.

R

Recessive: A genetic condition that appears only in individuals who have received two copies of a gene, one from each parent.

Retinal detachment: Tear or separation of the lining of the back of the eye.

S

Scoliosis: Curvature of the spine to one side.

Shprintzen-Goldberg syndrome: A connective tissue disorder caused by mutations in the SKI gene. This gene provides instructions for making a protein that controls the transforming growth factor beta (TGF- β) signaling pathway. Key features includes long arms, legs, and fingers; sunken or protruding chest, curved spine and craniosynostosis (an early fusion of the skull bones causing facial features such as a long, narrow head, widely spaced eyes, high, narrow roof of the mouth, and other facial abnormalities).

Spondylolithesis: Spinal condition where one vertebrae slips forward or backward in relation to the next vertebrae; symptoms can include low back pain, pain and/or muscle spasms in the thighs and lower leg, muscle weakness, and/or tightness in the hamstring muscle of the leg. Diagnosis is made from x-ray; can be congenital or develop over time.

Spontaneous mutation: A new permanent structural change in a gene that was not passed down from parent to child.

Sternum: Chest or breastbone.

Stickler syndrome: A genetic disorder caused by mutations in genes that are responsible for forming collagen, proteins which add strength and elasticity to connective tissue.

Strabismus: Deviation or misalignment of the eyes. Many people with Marfan syndrome have an outward deviation or turning of the eye (exotropia).

Striae: Stretch marks of the skin.

Syndrome: A group of physical characteristics that occur together.

T

TGFBR1: Transforming growth factor beta receptor 1.

TGFBR2: Transforming growth factor beta receptor 2.

Thoracic: Pertaining to or affecting the chest.

Thoracic aortic aneurysm and dissection: An enlargement of the aorta in the thoracic cavity (the chest area enclosed by the ribs and containing the lungs and the heart). If the aneurysm is not surgically repaired, it can lead to aortic dissection.

Translucent skin: When veins are easily visible under the skin.

V

Valve-sparing surgery: Surgery that preserves (spares) a person’s own aortic valve while replacing the aorta close to the heart with a woven tube (usually made of Dacron). It is a possible alternative to the more commonly used composite graft repair.

Variable expression: A range of features of any hereditary condition and of the severity of the condition.

Vertebrae: Bones of the spine.

Vertebral artery: Major artery in the neck that carries blood from the heart to the brain.

W

Weill-Marchesani syndrome: A connective tissue disorder characterized by abnormalities of the lens of the eye, short stature, shortness of the fingers and toes, and joint stiffness.