Down syndrome
Down syndrome (also written as Down's syndrome) is a genetic disorder caused by an extra chromosome, the chromosome 21.
The name comes from British physician John Langdom Down, who described the syndrome in 1862. Down named the condition mongoloism because the external appearance of its sufferers resembled the Mongolian race (one of the five racial classifications commonly used at the time). Currently, the terms "mongolism" and "mongoloid" are considered offensive.
The most important medical aspect of Down syndrome is mental retardation. Individuals with Down syndrome have mild to severe mental retardation (but the cases of extreme mental retardation are usually in those that were abandoned by their unloving parents).
Other characteristics of Down syndrome are (not all of them affect an individual):
- Single transverse palmar crease
- Eyes that look like those of elves
- Smaller limbs
- Weak muscle tone
- Bigger and protuse tongue
- Congenital heart defect
- Gastroesophageal reflux disease
- Otitis
- Sleep apnea
- Thyroid hormone problems
- Leukemia
There are evidences that people with Down syndrome have higher resistence to cancer.
Down syndrome is an universal phenomemon, affecting all nationalities. It's incorrect to call it a "disease", since it's not contagious.
