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February 10, 2012

Loeys-Dietz Syndrome Glossary of Terms

The following are health and medical definitions of terms that appear in the Loeys-Dietz Syndrome article.

Abnormal: Not normal. Deviating from the usual structure, position, condition, or behavior. In referring to a growth, abnormal may mean that it is cancerous or premalignant (likely to become cancer).

Aneurysm: A localized widening (dilatation) of an artery, vein, or the heart. At the area of an aneurysm, there is typically a bulge and the wall is weakened and may rupture. The word "aneurysm" comes from the Greek "aneurysma" meaning "a widening."
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Aorta: The largest artery in the body, the aorta arises from the left ventricle of the heart, goes up (ascends) a little ways, bends over (arches), then goes down (descends) through the chest and through the abdomen to where ends by dividing into two arteries called the common iliac arteries that go to the legs.
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Aortic: Pertaining to the aorta, the largest artery in the body.
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Aortic aneurysm: An outpouching (a local widening) of the largest artery in the body, the aorta, involving that vessel in its course above the diaphragm (thoracic aortic aneurysm) or, more commonly, below the diaphragm (abdominal aortic aneurysm). The diagnosis of an aortic aneurysm can be straight forward or difficult. Around 1900 the eminent physician William Osler said: "There is no disease more conducive to clinical humility than aneurysm of the aorta." At the area of the aneurysm, there is typically a bulge and the wall is weakened and may rupture. Because of the volume of blood flowing under relatively high pressure through the aorta, a ruptured aneurysm of the aorta is a catastrophe.
See the entire definition of Aortic aneurysm

Artery: A vessel that carries blood high in oxygen content away from the heart to the farthest reaches of the body. Since blood in arteries is usually full of oxygen, the hemoglobin in the red blood cells is oxygenated. The resultant form of hemoglobin (oxyhemoglobin) is what makes arterial blood look bright red.
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Autosomal: Pertaining to a chromosome that is not a sex chromosome; relating to any one of the chromosomes save the sex chromosomes.
See the entire definition of Autosomal

Autosomal dominant: A pattern of inheritance in which an affected individual has one copy of a mutant gene and one normal gene on a pair of autosomal chromosomes. (In contrast, autosomal recessive diseases require that the individual have two copies of the mutant gene.) Individuals with autosomal dominant diseases have a 50-50 chance of passing the mutant gene and therefore the disorder onto each of their children. Examples of autosomal dominant diseases include Huntington disease, neurofibromatosis, and polycystic kidney disease.

Brain: That part of the central nervous system that is located within the cranium (skull). The brain functions as the primary receiver, organizer and distributor of information for the body. It has two (right and left) halves called "hemispheres."

Chest: The area of the body located between the neck and the abdomen. The chest contains the lungs, the heart and part of the aorta. The walls of the chest are supported by the dorsal vertebrae, the ribs, and the sternum.
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Circulation: The movement of fluid in a regular or circuitous course. Although the noun "circulation" does not necessarily refer to the circulation of the blood, for all practical purposes today it does. Heart failure is an example of a problem with the circulation.

Cleft palate: An opening in the roof of the mouth (the palate) due to a failure of the palatal shelves to come fully together from either side of the mouth and fuse, as they normally should, during embryonic development.
See the entire definition of Cleft palate

Computerized tomography: Pictures of structures within the body created by a computer that takes the data from multiple X-ray images and turns them in pictures.
See the entire definition of Computerized tomography

Connective tissue: A material made up of fibers forming a framework and support structure for body tissues and organs. Connective tissue surrounds many organs. Cartilage and bone are specialized forms of connective tissue. All connective tissue is derived from mesoderm, the middle germ cell layer in the embryo.

Contrast: Short for "contrast media." Contrast media are X-ray dyes used to provide contrast, for example, between blood vessels and other tissue.

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Craniosynostosis: Premature fusion of the cranial sutures (the fibrous joints between the bones of the skull) in an infant, preventing normal growth of the baby's head. Craniosynostosis involving some but not all of the sutures causes an abnormally shaped skull. Premature closure of all of the sutures results in microcephaly (an abnormally small head) which arrests the normal growth and development of the baby's brain and may result in developmental delay and mental retardation. Early detection of the condition is therefore of great importance. Treatment is surgery designed to keep the sutures open.
See the entire definition of Craniosynostosis

Diagnosis: 1 The nature of a disease; the identification of an illness. 2 A conclusion or decision reached by diagnosis. The diagnosis is rabies. 3 The identification of any problem. The diagnosis was a plugged IV.
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Ehlers-Danlos syndrome: A heritable disorder of connective tissue with easy bruising, joint hypermobility (loose joints), skin laxity, and weakness of tissues. There are a number of different types of Ehlers-Danlos syndrome (EDS) which share the foregoing features but can be categorized into at least nine different types:
See the entire definition of Ehlers-Danlos syndrome

Essential: 1. Something that cannot be done without.
2. Required in the diet, because the body cannot make it. As in an essential amino acid or an essential fatty acid.
3. Idiopathic. As in essential hypertension. "Essential" is a hallowed term meaning "We don't know the cause."

Family history: The family structure and relationships within the family, including information about diseases in family members.
See the entire definition of Family history

Gene: The basic biological unit of heredity. A segment of deoxyribonucleic acid (DNA) needed to contribute to a function.
See the entire definition of Gene

Genes: The basic biological units of heredity. Segments of deoxyribonucleic acid (DNA) needed to contribute to a function.
See the entire definition of Genes

Genetic: Having to do with genes and genetic information.

Genetic testing: Tests done for clinical genetic purposes. Genetic tests may be done for diverse purposes pertaining to clinical genetics, including the diagnosis of genetic disease in children and adults; the identification of future disease risks; the prediction of drug responses; and the detection of risks of disease to future children.

Heart: The muscle that pumps blood received from veins into arteries throughout the body. It is positioned in the chest behind the sternum (breastbone; in front of the trachea, esophagus, and aorta; and above the diaphragm muscle that separates the chest and abdominal cavities. The normal heart is about the size of a closed fist, and weighs about 10.5 ounces. It is cone-shaped, with the point of the cone pointing down to the left. Two-thirds of the heart lies in the left side of the chest with the balance in the right chest.
See the entire definition of Heart

Loeys-Dietz syndrome: Loeys-Dietz syndrome is an inherited syndrome characterized by aortic aneurysms (weakened outpouchings of the aorta) and other blood vessel abnormalities in children. Other physical characteristics may be associated with Loeys-Dietz syndrome, including early fusion of the skull bones (known as craniosynostosis), widely spaced eyes, and cleft palate or split uvula. The severity of the visible physical characteristics varies among affected individuals. One important difference among Loeys-Dietz syndrome and other inheritable causes of aortic aneurysms is that the aortic aneurysms of Loeys-Dietz syndrome are prone to rupture at a smaller size than other aneurysms, with early identification of the condition and surgical intervention critical for survival.

Magnetic resonance imaging: A special radiology technique designed to image internal structures of the body using magnetism, radio waves, and a computer to produce the images of body structures. In magnetic resonance imaging (MRI), the scanner is a tube surrounded by a giant circular magnet. The patient is placed on a moveable bed that is inserted into the magnet. The magnet creates a strong magnetic field that aligns the protons of hydrogen atoms, which are then exposed to a beam of radio waves. This spins the various protons of the body, and they produce a faint signal that is detected by the receiver portion of the MRI scanner. A computer processes the receiver information, and an image is produced. The image and resolution is quite detailed and can detect tiny changes of structures within the body, particularly in the soft tissue, brain and spinal cord, abdomen and joints.
See the entire definition of Magnetic resonance imaging

Marfan syndrome: An inherited disorder of connective tissue characterized by abnormalities of the eyes, skeleton, and cardiovascular system.
See the entire definition of Marfan syndrome

Molecule: The smallest unit of a substance that can exist alone and retain the character of that substance.

MRI: Abbreviation and nickname for magnetic resonance imaging. For more information, see: Magnetic Resonance Imaging; Paul C. Lauterbur; Peter Mansfield.

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Mutation: A permanent change, a structural alteration, in the DNA or RNA. In humans and many other organisms, mutations occur in DNA. However, in retroviruses like HIV, mutations occur in RNA which is the genetic material of retroviruses.
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New England Journal of Medicine: Despite its regional name, The New England Journal of Medicine (NEJM) is far from provincial. It is an eminent weekly national and international general medical journal, devoted to no single specialty, but to all of medicine. The Journal is published by the Massachusetts Medical Society and is closely associated with the medical schools (Boston University, Harvard and Tufts) in the Boston area.
See the entire definition of New England Journal of Medicine

Osteoporosis: Thinning of the bones with reduction in bone mass due to depletion of calcium and bone protein. Osteoporosis predisposes a person to fractures, which are often slow to heal and heal poorly. It is more common in older adults, particularly post-menopausal women; in patients on steroids; and in those who take steroidal drugs. Unchecked osteoporosis can lead to changes in posture, physical abnormality (particularly the form of hunched back known colloquially as "dowager's hump"), and decreased mobility.
See the entire definition of Osteoporosis

Palate: The roof of the mouth. The front portion is bony (hard palate), and the back portion is muscular (soft palate).

Pediatric: Pertaining to children.

Pelvis: The lower part of the abdomen located between the hip bones.

Prognosis: 1. The expected course of a disease.
2. The patient's chance of recovery.
The prognosis predicts the outcome of a disease and therefore the future for the patient. His prognosis is grim, for example, while hers is good.
See the entire definition of Prognosis

Receptor: 1. In cell biology, a structure on the surface of a cell (or inside a cell) that selectively receives and binds a specific substance. There are many receptors. There is a receptor for (insulin; there is a receptor for low-density lipoproteins (LDL); etc. To take an example, the receptor for substance P, a molecule that acts as a messenger for the sensation of pain, is a unique harbor on the cell surface where substance P docks. Without this receptor, substance P cannot dock and cannot deliver its message of pain. Variant forms of nuclear hormone receptors mediate processes such as cholesterol metabolism and fatty acid production. Some hormone receptors are implicated in diseases such as diabetes and certain types of cancer. A receptor called PXR appears to jump-start the body's response to unfamiliar chemicals and may be involved in drug-drug interactions.
2. In neurology, a terminal of a sensory nerve that receives and responds to stimuli.

Recessive: A condition that appears only in individuals who have received two copies of a mutant gene, one copy from each parent. The individuals with a double dose of the mutated gene are called homozygotes. Their parents, each with a single dose of the mutated gene, appear normal and are called heterozygotes, or gene carriers.
See the entire definition of Recessive

Rupture: A break or tear in any organ (such as the spleen) or soft tissue (such as the achilles tendon). Rupture of the appendix is more likely among uninsured and minority children when they develop appendicitis.

Skull: The skull is a collection of bones which encase the brain and give form to the head and face. The bones of the skull include the following: the frontal, parietal, occipital, temporal, sphenoid, ethmoid, zygomatic, maxilla, nasal, vomer, palatine, inferior concha, and mandible.
See the entire definition of Skull

Spine: 1) The column of bone known as the vertebral column, which surrounds and protects the spinal cord. The spine can be categorized according to level of the body: i.e., cervical spine (neck), thoracic spine (upper and middle back), and lumbar spine (lower back). See also vertebral column. 2) Any short prominence of bone. The spines of the vertebrae protrude at the base of the back of the neck and in the middle of the back. These spines protect the spinal cord from injury from behind.

Surgery: The word "surgery" has multiple meanings. It is the branch of medicine concerned with diseases and conditions which require or are amenable to operative procedures. Surgery is the work done by a surgeon. By analogy, the work of an editor wielding his pen as a scalpel is s form of surgery. A surgery in England (and some other countries) is a physician's or dentist's office.
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Syndrome: A set of signs and symptoms that tend to occur together and which reflect the presence of a particular disease or an increased chance of developing a particular disease.
See the entire definition of Syndrome

Tomography: The process for generating a tomogram, a two-dimensional image of a slice or section through a three-dimensional object. Tomography achieves this remarkable result by simply moving an x-ray source in one direction as the x-ray film is moved in the opposite direction during the exposure to sharpen structures in the focal plane, while structures in other planes appear blurred. The tomogram is the picture; the tomograph is the apparatus; and tomography is the process.
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Uvula: The small piece of soft tissue that can be seen dangling down from the soft palate over the back of the tongue. The uvula is described variously shaped like a U, a tear or a grape. Its name comes from the Latin word for "grape," uva.
See the entire definition of Uvula

Vascular: Relating to the blood vessels of the body. The blood vessels of the body, as a group, are referred to as the vascular system.
See the entire definition of Vascular

X-ray: 1. High-energy radiation with waves shorter than those of visible light. X-rays possess the properties of penetrating most substances (to varying extents), of acting on a photographic film or plate (permitting radiography), and of causing a fluorescent screen to give off light (permitting fluoroscopy). In low doses X-rays are used for making images that help to diagnose disease, and in high doses to treat cancer. Formerly called a Roentgen ray. 2. An image obtained by means of X-rays.

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  • Related Diseases & Conditions

    • Abdominal Aortic Aneurysm
      • Abdominal aortic aneurysm is a ballooning or widening of the main artery (the aorta) as it courses down through the abdomen. The most common cause of aortic aneurysms is "hardening of the arteries" called arteriosclerosis.
    • Marfan Syndrome
      • Marfan syndrome is hereditary condition affecting connective tissue. A person with Marfan syndrome may exhibit the following symptoms and characteristics: dislocation of one or both lenses of the eye; a protruding or indented breastbone; scoliosis; flat feet; aortic dilatation; dural ectasia; stretch marks; hernia; and lung collapse. Though there is no cure for Marfan syndrome, there are treatments that can minimize and sometimes prevent some complications.
    • Ehlers-Danlos Syndrome
      • Ehlers-Danlos syndromes are genetic disorders that include symptoms such as loose joints, tissue weakness, easy bruising, and skin that stretches easily. There are seven types of Ehlers-Danlos syndromes: Classical type, Hypermobility type, Vascular type, Kyphoscoliosis type, Arthrochalsia type, Dermatosparaxis type, and Tenascin-X Deficient type. Treatment for Ehlers-Danlos syndromes depends on which symptoms are present.
    • Genetic Disease
      • Genetic disease is a disorder or condition caused by abnormalities in a person's genome. Types of genetic inheritance include single inheritance (for example, cystic fibrosis, sickle cell anemia, Marfan syndrome, and hemochromatosis), multifactoral inheritance, chromosome abnormalities (for example, Turner syndrome, and Klinefelter syndrome), and mitochondrial inheritance (for example, epilepsy and dementia).
    • Birth Defects
      • Birth defects have many causes and currently, are the leading cause of death for infants in the first year of life. Some of the causes of birth defects include genetic or chromosome problems. Exposure of the mother to rubella or German measles during pregnancy, or using drugs or alcohol during pregnancy. The treatment for birth defects depends upon the condition of the effected child.
    • Congenital Heart Defects
    • Cleft Palate and Cleft Lip
      • Cleft palate and cleft lip are facial and oral defects that occur early in pregnancy. A cleft lip is a split of the two sides of the upper lip, and a cleft palate is a split in the roof of the mouth. Cleft lip the fourth most common birth defect in the U.S. Repair of a cleft palate or cleft lip may require multiple surgeries.
    • Genetic Counseling
      • Your health care provider may refer you to a genetic professional. Universities and medical centers also often have affiliated genetic professionals, or can provide referrals to a genetic professional or genetics clinic. Genetic counseling provides patients and family members the tools to make the right choice in regard to test for a disease or condition.
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Loeys-Dietz Syndrome

What are genetic professionals and what do they do?

Genetics professionals are health care professionals with specialized degrees and experience in medical genetics and counseling. Genetics professionals include geneticists, genetic counselors and genetics nurses.

What is genetic counseling and evaluation?

Genetic professionals work as members of health care teams providing information and support to individuals or families who have genetic disorders or may be at risk for inherited conditions. Genetic professionals:

  • Assess the risk of a genetic disorder by researching a family's history and evaluating medical records.
  • Weigh the medical, social and ethical decisions surrounding genetic testing.
  • Provide support and information to help a person make a decision about testing.
  • Interpret the results of genetic tests and medical data.
  • Provide counseling or refer individual...

Read the Genetic Counseling article »




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