Genetic Disorders Project

Down's Syndrome


Down's syndrome can be caused by an accident during cell division resulting in an extra 21st chromosome. Normally occurs in mothers age 44 and over.


Most cases of down's syndrome are not inherited; it happens as a random event during the forming of reproductive cells in a parent. The accident can happen in the sperm or the egg cell, normally being the egg. The accident or error during cell division is called nondisjunction meaning that when the cells split one of them may gain an extra copy of chromosome 21. Nondisjunction happens so early in these atypical cells causes every cell in the organism's body to contain an extra 21st chromosome.

More Prevalent

Down's syndrome is not more prevalent in any single group of people. Some say that it is more common in Caucasians but that's because they're usually the ones to have children later in life.


People with down's syndrome are usually short in height with a short, wide neck. Their arms and legs are short and stocky. When it comes to facial features their eyes are slanted and small ears. They have an irregularly shaped mouth which causes their tongue to stick out. Many health problems also come with down's syndrome: heart defects, intellectual disability, respiratory infections and behavioral problems and eye problems may also occur.

Life Expectancy

The average life expectancy for people with down's syndrome can be anywhere from 55 years old to some living in their 60's. With proper medical care, people with down's syndrome can live long and healthy lives.


There is no special treatment for down's syndrome. How ever, throughout their life they need to be treated for the health problems that come with down's syndrome.