MedicineNet.com

About Us|Privacy Policy|Site Map
February 10, 2012

Prader-Willi Syndrome Glossary of Terms

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

Cell: The basic structural and functional unit in people and all living things. Each cell is a small container of chemicals and water wrapped in a membrane.
See the entire definition of Cell

Chromosome: A visible carrier of the genetic information.
See the entire definition of Chromosome

Chromosomes: The microscopically visible carriers of the genetic material. They are composed of deoxyribonucleic acid (DNA) and proteins and, under a microscope, look like little rods.
See the entire definition of Chromosomes

Chronic: This important term in medicine comes from the Greek chronos, time and means lasting a long time.
See the entire definition of Chronic

Contiguous gene syndrome: A disorder due to deletion of multiple gene loci that are adjacent to one another. Contiguous gene syndromes are characterized by multiple, apparently unrelated, clinical features caused by deletion of the multiple adjacent genes. Each of the individual genes within a contiguous region, when mutated, gives rise to a distinct feature.
See the entire definition of Contiguous gene syndrome

Deletion: Loss of a segment of DNA from a chromosome (and hence from the genome).
See the entire definition of Deletion

Diabetes: Refers to diabetes mellitus or, less often, to diabetes insipidus. Diabetes mellitus and diabetes insipidus share the name "diabetes" because they are both conditions characterized by excessive urination (polyuria).
See the entire definition of Diabetes

Diabetes mellitus: Better known just as "diabetes" -- a chronic disease associated with abnormally high levels of the sugar glucose in the blood. Diabetes is due to one of two mechanisms:
(1) Inadequate production of insulin (which is made by the pancreas and lowers blood glucose) or
(2) Inadequate sensitivity of cells to the action of insulin.
The two main types of diabetes correspond to these two mechanisms and are called insulin dependent (type 1) and non-insulin dependent (type 2) diabetes. In type 1 diabetes there is no insulin or not enough of it. In type 2 diabetes, there is generally enough insulin but the cells upon it should act are not normally sensitive to its action.
See the entire definition of Diabetes mellitus

DNA: Deoxyribonucleic acid. One of two types of molecules that encode genetic information. (The other is RNA. In humans DNA is the genetic material; RNA is transcribed from it. In some other organisms, RNA is the genetic material and, in reverse fashion, the DNA is transcribed from it.)
See the entire definition of DNA

Father: (1) The male parent. (2) One who originates. For example, "Wilhelm Roentgen is considered the father of radiology." (3) To produce offspring as a male. (4) To provide paternal protection and guidance to children.

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.

Genetics: The scientific study of heredity. Genetics pertains to humans and all other organisms. So, for example, there is human genetics, mouse genetics, fruitfly genetics, etc.
See the entire definition of Genetics

Genomic: Pertaining to the genome, all of the genetic information possessed by any organism.
See the entire definition of Genomic back to top

Genomic imprinting: The phenomenon of parent-of-origin gene expression. The expression of a gene depends upon the parent who passed on the gene.
See the entire definition of Genomic imprinting

Hypogonadism: A condition in which decreased production of gonadal hormones leads to below-normal function of the gonads and to retardation of sexual growth and development. (The gonads are the ovaries and testes and the hormones they normally produce include estrogen, progesterone, and testosterone.)

Hypotonia: Decreased tone of skeletal muscles. In a word, floppiness. Hypotonia is a common finding in cerebral palsy and other neuromuscular disorders. Untreated hypotonia can lead to hip dislocation and other problems. Treatment is via physical therapy. In some cases braces may be needed to permit a full range of movement despite hypotonia.

Infertile: Not able to conceive after a year of regular intercourse without contraception.
See the entire definition of Infertile

Learning disability: A childhood disorder characterized by difficulty with certain skills such as reading or writing in individuals with normal intelligence. Learning disorders affect the ability to interpret what one sees and hears or the ability to link information from different parts of the brain. These limitations can show up in many ways -- as specific difficulties with spoken and written language, coordination, self-control, or attention. Such difficulties extend to schoolwork and can impede learning to read or write, or to do math.
See the entire definition of Learning disability

Maternal: 1. Pertaining to the mother as, for example, the maternal mortality rate. 2. Related through the mother as, for example, the maternal grandparents. 3. Inherited from the mother as, for example, the maternal X chromosome.

Mental retardation: A term used when a person has certain limitations in mental functioning and in skills such as communicating, taking care of him or herself, and social skills. These limitations will cause a child to learn and develop more slowly than a typical child. Children with mental retardation may take longer to learn to speak, walk, and take care of their personal needs such as dressing or eating. They are likely to have trouble learning in school. They will learn, but it will take them longer. There may be some things they cannot learn. As many as 3 out of every 100 people have mental retardation. In fact, 1 out of every 10 children who need special education has some form of mental retardation.
See the entire definition of Mental retardation

Muscle: Muscle is the tissue of the body which primarily functions as a source of power. There are three types of muscle in the body. Muscle which is responsible for moving extremities and external areas of the body is called "skeletal muscle." Heart muscle is called "cardiac muscle." Muscle that is in the walls of arteries and bowel is called "smooth muscle."

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.
See the entire definition of Mutation

NIH: The National Institutes of Health. The NIH is an important U.S. health agency. It is devoted to medical research. Administratively under the Department of Health and Human Services (HHS), the NIH consists of 20-some separate Institutes and Centers. NIH's program activities are represented by these Institutes and Centers.
See the entire definition of NIH

Obesity: The state of being well above one's normal weight.
See the entire definition of Obesity

Paternal: 1. Pertaining to the father as, for example, a paternal age effect.
2. Related through the father as, for example, the paternal grandparents.
3. Inherited from the father as, for example, the paternal X chromosome.

Pigmentation: The coloring of the skin, hair, mucous membranes, and retina of the eye.
See the entire definition of Pigmentation

Prader-Willi syndrome: A syndrome characterized by severe hypotonia (floppiness), poor suck and feeding problems in early infancy followed later in infancy by excessive eating that, if unchecked, leads gradually to huge obesity. All children with Prader-Willi syndrome (PWS) show developmental delay and mild-to-moderate mental retardation with multiple learning disabilities. Hypogonadism is present in both females (with small labia minora and clitoris) and males (with underdeveloped scrotum and nondescent of the testes). Short stature and small hands and feet are common.
See the entire definition of Prader-Willi syndrome

Protein: A large molecule composed of one or more chains of amino acids in a specific order determined by the base sequence of nucleotides in the DNA coding for the protein.
See the entire definition of Protein back to top

Puberty: A complex biologic and psychologic process involving sexual development, accelerated growth, and adrenal maturation heralded by the secretion of gonadotropin releasing hormone (GnRH) from a part of the brain called the hypothalamus. This event is the first known step in the reproductive cascade. It initiates the pulsatile release of gonadotropins, gonadal secretion of sex steroids, pubertal development, and gametogenesis (the production of sperm and ova).
See the entire definition of Puberty

Random: The process by which an outcome is determined solely by chance, for example, by a coin flip.
See the entire definition of Random

Reproductive cells: The eggs and sperm are the reproductive cells. Each mature reproductive cell is haploid in that it has a single set of 23 chromosomes containing half the usual amount of DNA.
See the entire definition of Reproductive cells

Sleep: The body's rest cycle.
See the entire definition of Sleep

Sperm: A sperm is the male "gamete" or sex cell. It combines with the female "gamete," called an ovum, to form a zygote. The formation process is called "fertilization." (see ovum, zygote).

Symptom: Any subjective evidence of disease. Anxiety, lower back pain, and fatigue are all symptoms. They are sensations only the patient can perceive. In contrast, a sign is objective evidence of disease. A bloody nose is a sign. It is evident to the patient, doctor, nurse and other observers.

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

Type 2 diabetes: See Diabetes, type 2.

back to top

MedicineNet Doctors

Suggested Reading on Prader-Willi Syndrome by Our Doctors

  • Related Diseases & Conditions

    • Obesity
      • Obesity is the state of being well above one's normal weight. A person has traditionally been considered to be obese if they are more than 20 percent over their ideal weight. That ideal weight must take into account the person's height, age, sex, and build.
    • Learning Disabilities
      • Learning disabilities can cause an individual to have trouble learning and using skills such as reading, listening, writing, reading, speaking, reasoning, and performing mathematics. There is no cure for learning disabilities. Parents and teachers working together to properly diagnose learning disabilities can properly plan a course of education. For some, medication may be appropriate as complimentary treatment.
    • Puberty
      • The time when boys and girls begin the process of sexual maturation is called puberty. During this time, both sexes undergo a series of biological changes that include a rapid increase in height, bone growth, weight increase, the growth of pubic hair, breast development and the onset of menstruation in girls, and testicle, penis, and muscle enlargement in boys.
    • 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).
    • Angelman Syndrome
      • Angelman syndrome is a genetic disorder that results from the absence of a functional copy of the UBE3A gene inherited from the mother. Infants with Angelman syndrome often have feeding problems and exhibit noticeable developmental delays by six to 12 months of age. Other symptoms include seizures, hyperactivity, speech impairment, small head size, sleep disorders, and movement and balance disorders. There is no specific treatment or therapy for Angelman syndrome.
    • Childhood Obesity
      • Fast food consumption and lack of exercise are just a couple of causes of childhood obesity. Health effects of childhood obesity include type 2 diabetes, heart attack, stroke, high cholesterol, asthma, sleep apnea, gallstones, fatty liver disease, GERD, depression, and eating disorders.
    • 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.
  • Medications

  • Procedures & Tests

  • Pictures, Images & Illustrations

  • Doctor's & Expert's Views

  • Health News

  • Health Features

Women's Health

Find out what women really need.



Symptom Checker: Your Guide to Symptoms & Signs: Pinpoint Your Pain


Prader-Willi Syndrome

What is obesity?

The definition of obesity varies depending on what one reads, but in general, it is a chronic condition defined by an excess amount body fat. A certain amount of body fat is necessary for storing energy, heat insulation, shock absorption, and other functions. The normal amount of body fat (expressed as percentage of body fat) is between 25%-30% in women and 18%-23% in men. Women with over 30% body fat and men with over 25% body fat are considered obese.

The calculation of body mass index (BMI) has also been used in the definition of obesity. The body mass index (BMI) equals a person's weight in kilograms (kg) divided by their height in meters (m) squared. Since BMI describes body weight relative to height, it is strongly correlated with total body fat content in adults. "Obesity" is defined as a BMI of 30 and above.

How common is obesity?

Obesity has reached epidemic proportions in the United States. One i...

Read the Obesity article »




Use Pill Finder Find it Now

Pill Identifier on RxList

  • quick,
    easy,
    pill identification

Find a Local Pharmacy

  • including
    24 hour
    pharmacies