dwarfism

dwarfism

[dwawr-fiz-uhm]
dwarfism, condition in which an animal or plant is less than normal in size and lacks the capacity for normal growth. Dwarfism is deliberately produced and perpetuated in certain species (e.g., in breeding miniature dogs and cultivating dwarf plants). Among humans, dwarfism usually results from a combination of genetic factors and endocrine malfunction. It can also be caused, however, by acquired conditions, such as kidney disease. Pituitary dwarfism is caused by an insufficiency of the pituitary growth hormone (hypopituitary dwarfism). Typically, the pituitary dwarf stops growing in early childhood but retains normal body proportion, mental capacity, and sexual development. Pharmaceutical companies are cloning human growth hormone to stimulate growth in children afflicted with hypopituitary glands. This type of dwarf, who is completely normal except for size, is commonly called a midget. Cretinism is a type of dwarfism accompanied by mental retardation and distortion of the body, resulting from an insufficiency of thyroid hormone. Unlike cretinism and pituitary dwarfism (which are thought to be caused by a combination of heredity and endocrine malfunction), achondroplastic dwarfism is the result of a completely hereditary, dominant genetic trait. Typically, the growth of the limbs is stunted, but the size of the trunk and mental capacity are normal. Humans who range in height from 2 to 4 ft (5.08-10.16 cm) are generally classified as dwarfs. However, small size that is an inherited characteristic of race (such as among African Pygmies) is not considered to be dwarfism since the individuals in such groups are physiologically normal.

Growth retardation resulting in abnormally short adult stature. It is caused by a variety of hereditary and metabolic disorders. Pituitary dwarfism is caused by insufficient growth hormone. Hereditary dwarfisms include achondroplasia, with normal trunk size but short limbs and a large head; hypochondroplasia, similar except for normal head size; and diastrophic dwarfism, with progressive, crippling skeletal deformities. Intelligence is normal in these forms of dwarfism. Some kinds include intellectual disability. Dwarfism may also result from inadequate nutrition in early life (see rickets).

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Dwarfism is a medical condition in humans characterized by extreme small size. The most widely accepted definition in medical biology for a dwarf is a person with an adult height of less than 4 feet 10 inches (147cm). In older popular and medical usage, any type of marked human smallness could also be termed dwarfism.

Dwarfism can be caused by more than 200 different medical conditions. The most common cause of dwarfism is achondroplasia, a bone growth disorder responsible for 70% of dwarfism cases. Conditions in humans characterized by disproportional body parts are typically caused by one or more genetic disorders in bone or cartilage development. Achondroplasia is an example of disproportional dwarfism. Forms of extreme shortness in humans characterized by proportional body parts usually have a hormonal or nutritional cause. An example is growth hormone deficiency, once known as "pituitary dwarfism".

Types of dwarfism

  • rhizomelic = root, e.g. bones of upper arm or thigh
  • mesomeli = middle, e.g. bones of forearm or lower leg
  • acromelic = end, e.g. bones of hands and feet.

When the cause of dwarfism is understood, it may be classified according to one of hundreds of names, which are usually permutations of the following roots:

  • chondro = of cartilage
  • osteo = of bone
  • spondylo = of the vertebrae
  • plasia = form
  • trophy = growth

Examples include achondroplasia, osseous dysplasia, chondrodystrophy, and osteochondrodystrophy.

The most recognizable and most common form of dwarfism is achondroplasia, which produces rhizomelic short limbs, increased spinal curvature, and distortion of skull growth. It accounts for 70% of dwarfism cases. Other relatively common types include spondyloepiphyseal dysplasia congenita (SED), diastrophic dysplasia, pseudoachondroplasia, hypochondroplasia, and osteogenesis imperfecta (OI). Severe shortness with skeletal distortion also occurs in several of the mucopolysaccharidoses and other storage diseases.

The average adult height of male and females with dwarfism is 132 cm and 123 cm respectively. The average weight of an adult may range from 100 to 150 pounds (45-68 kg).

Diagnosis

Unusually short stature for a child's age is usually what brings the child to medical attention. Skeletal dysplasia ("dwarfism") is usually suspected because of obvious physical features (e.g., unusual configuration of face or shape of skull), because of an obviously affected parent, or because body measurements (arm span, upper to lower segment ratio) indicate disproportion. Bone x-rays are often the key to diagnosis of a specific skeletal dysplasia, but they are not the key diagnosis. Most children with suspected skeletal dysplasias will be referred to a genetics clinic for diagnostic confirmation and genetic counseling. In the last decade, genetic tests for some of the specific disorders have become available.

During the initial medical evaluation for shortness, the absence of disproportion and the other clues above usually indicates other causes than bone dysplasias. Extreme shortness with completely normal proportions sometimes indicates growth hormone deficiency (pituitary dwarfism).

Short stature alone, in the absence of any other abnormalities, may simply be genetic, particularly if a person is born into a family of people who are relatively short.

Problems associated with dwarfism

The principal adverse effects of dwarfism can be divided into the physical and the social.

Physical effects of malformed bones vary according to the specific disease. Many involve pain resulting from joint damage from abnormal bone alignment, or from nerve compression (e.g, spinal stenosis).. Early degenerative joint disease, exaggerated lordosis or scoliosis, and constriction of spinal cord or nerve roots can cause pain and disability. Reduced thoracic size can restrict lung growth and reduce pulmonary function. Some forms of dwarfism are associated with disordered function of other organs, such as the brain or liver, sometimes severely enough to be more disabling than the abnormal bone growth. As well, many dwarves are given injections of Human Growth Hormone during their early years, in the hope that it will increase their height, though, sadly, the HGH injections may cause adverse effects on the cardiac muscles, making them too large or thick to properly function, causing death through cardiac failure in the patient.

The psychosocial disadvantages may be more distressing than the physical symptoms, especially in childhood and adolescence, but people with dwarfism vary greatly in the degree to which social participation and emotional health are affected.

  • Social prejudice against extreme shortness may reduce social and marital opportunities.
  • Numerous studies have demonstrated reduced employment opportunities. Severe shortness is associated with lower income.
  • Self-esteem may suffer and family relationships affected
  • Extreme shortness (in the low 2–3 foot [60–90 cm] range) can interfere with ordinary activities of daily living, like driving or even using countertops built for taller people. There are also symptoms with dwarfism such as bowed knees, big head and forehead, back problems, difficulty walking, and unusually short fingers.
  • Dwarfism is often misunderstood by others and short people are often believed to be academically challenged, which leads to a difficult social life.

Treatment and support

As the genetic defects of most forms of dwarfism due to bone dysplasia cannot be corrected, therapeutic interventions are typically aimed at (1) preventing or reducing pain or physical disability, (2) increasing adult height, or (3) mitigating psychosocial stresses and enhancing social adaptation.

Pain and disability may be ameliorated by physical therapy, by braces or other orthotic devices, or by surgical procedures. The only simple interventions that increase perceived adult height are dress enhancements such as shoe lifts or hairstyle. Growth hormone is rarely used for shortness due to bone dysplasias, as the height benefit is typically small (less than 5 cm) and the cost high. The most effective means of increasing adult height by several inches is limb-lengthening surgery, though availability is limited and cost is high in terms of money, discomfort, and interruption of life. Most people with dwarfism do not avail themselves of this, and it remains controversial. For other types of dwarfism, surgical treatment is not possible.

Cultural references

When depicted in art, literature, or movies, dwarves are rarely depicted as "regular people who are very short" but often as a species apart. Novelists, artists, and moviemakers attach special moral or aesthetic significance to the "apartness" or the misshapenness.

Artistic representations of dwarfism can be found on Greek vases and other ancient artefacts, including ancient Egyptian art. Documentation of dwarves can also be found on European paintings and many pictures. Many European paintings (especially Spanish) of the 16th–19th centuries depict dwarves by themselves or with others. In the Talmud, it is said that the second born son of the Egyptian Pharaoh of the Bible was a dwarf. Recent scholarship has indicated that the ancient Egyptians esteemed dwarves.

In Jonathan Swift's "Gulliver's Travels", the protagonist encounters in the court of the Giants' Kingdom the strong enmity of the local "dwarf", who is "only" twenty feet high (where normal giants measure forty feet) and resents being displaced by "a smaller dwarf".

Several novels have treated dwarfism as a major theme, although not necessarily realistically:

The actor and stunt man Verne Troyer has become famous playing the character "Mini-Me" in two Austin Powers movies, as has fellow stuntman and Jackass cast-member, Jason "Wee-Man" Acuña .

In the mid-1970s, Sid and Marty Krofft built an indoor theme park in Atlanta, Georgia called The World of Sid and Marty Krofft. This had a live stage production that was at that time the largest gathering of "little people" since the filming of The Wizard of Oz in 1937-38 as well as being the largest indoor theme park built to that time. The facility that was built to house this theme park is today the studios of CNN, the Cable News Network, and CNN Headline News.

In the 1990s, Seinfeld featured a dwarf character, Mickey Abbott, in seven episodes; Mickey was played by actor Danny Woodburn. He got into several physical altercations with -plus Kramer. In one episode, he was ostracized by his dwarf peers for using lifts in his shoes to make him look taller.

Arguably the most famous dwarf actor is Warwick Davis, having found success in several notable fantasy franchises, including Star Wars, Harry Potter, Willow, Leprechaun, Gulliver's Travels, The 10th Kingdom,The Hitchhiker's Guide to the Galaxy (film) and The Chronicles of Narnia (both the 1989 television serial and again in the 2008 film version of Prince Caspian). Deep Roy is also another fellow actor with dwarfism. Roy has acted in many movies such as Star Wars as an Ewok and in his most famous role, an Oompa Loompa in Charlie and the Chocolate Factory.

In George R.R. Martin's A Song of Ice and Fire series, one of the main characters, Tyrion Lannister, is a dwarf. Though a brilliant and well-read man (some would say genius), he struggles with acceptance by "normal" people, who pejoratively refer to him as "the Imp", or "half-man". This is especially true of his father, Lord Tywin Lannister, who holds Tyrion in contempt, especially when compared to Tyrion's handsome, talented older brother Jaime, and Jaime's equally beautiful and talented twin sister, Cersei. Tyrion often wonders if any woman could ever truly love him in spite of his condition.

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