Teresa Wooten, age 10, of Charleston, W. Va., for her question:
WHAT CAUSES MIDGETS AND DWARFS?
One type of dwarfism is called nonhormonal, and it occurs if disease or improper nourishment blocks the growth of cartilage cells. Sometimes a disease of the bowel or kidneys may interfere with growth, too. Doctors have found that nonhormonal interferences with growth often can be corrected with rapid catch up growth occurring after treatments have been given.
A dwarf is an unusually small adult human being, animal or plant. Human dwarfs are no taller than four and a half feet.
If the tiny human has normal body proportions, he is called a midget. If he has abnormal proportions, he is called a dwarf.
Dwarfism can occur in individual organisms and also in large groups of organisms. In Africa, for example, there are large groups of tiny people called Pygmies. You'll find tiny Shetland ponies, miniature and toy dogs, dwarf cattle, small trees including ornamental fruit trees and several varieties of dwarf flowers. In most cases, dwarfism happens as a result of defective cells, disease or poor nutrition.
In the human, dwarfism happens when the cartilage cells do not grow and divide properly. Sometimes the defect is restricted to the cartilage cells alone and other times it is a more widespread cellular disorder.
Chrondrodystrophic dwarfism happens when certain cells are underdeveloped. Most dwarfs of this type have abnormal body proportions. The defective cells can be found only in the spine or only in the legs and arms. As a result, either the chest, abdomen and hips or the limbs are extremely short.
Chromosome related dwarfism happens when all of the cells in the body, including the cartilage cells, are defective. One such disorder is called Turner's Syndrome.
Hormonal dwarfism happens when a hormone deficiency interferes with the growth of normal cartilage. An insufficient amount of growth promoting hormone (GH) results in stunted growth. Such a shortage can result in a dwarf with normal proportions.
A lack of insulin can lead to the disease diabetis mellitus, and a shortage from birth of thyroxine can cause cretinism. Both of these disorders interfere with growth and may lead to dwarfism.
Some children with a lack of certain growth promoting hormones may be treated successfully by doctors. Since the 1960s, medical men have been giving GH with good results. Only limited amounts of GH are available, however, and many children remain untreated.
Insulin and thyroxine, which can be easily obtained, are being given to many children to stimulate growth which has been affected by diabetes or cretinism.