Genetic Testing Down Syndrome

Submitted by Medical Health Test Team on October 16, 2012

Normal healthy human beings have 23 pairs of chromosomes in their bodies. These chromosomes are responsible for various traits and characteristics. There is a condition known as Down Syndrome which occurs when there is a 3rd chromosome in the 21st pairing. Hence this 21st pairing is actually 3 instead of the normal 2 chromosomes. There are physical and mental issues that are associated with Down Syndrome. Some physical issues associated with the condition include oblique eye fissures, weak muscles, small oral cavity, protruding tongue, small chin, round face and other issues that are not visible such as heart trouble. The mental issues associated with Down Syndrome include retardation which could be mild or severe depending on the variation and severity of the condition.

The physical characteristics of a patient with Down Syndrome are often corrected by plastic surgery. This is more common in patients who have a very slightly diminished intelligence quotient, making them otherwise normal. The social stigma attached to having odd facial features can cause problems throughout the life of a Down Syndrome patient. This justifies the use of plastic surgery which can allow a patient to lead a relatively normal life. Plastic surgery is also essential when the physical deformity causes some impediment or problem with living a normal life.

The only way to determine if a child will be born with Down Syndrome is by using genetic tests. Genetic testing for Down Syndrome could be conducted right from the 11th week onwards. There are some tests that are invasive and some that are non-invasive. The non invasive tests include an Expanded AFP Blood Test, conducted around 16 weeks into pregnancy, and the Nuchal Translucency Test conducted around the 12th or 13th week. The blood test is like a typical blood test whereas the NT test uses an ultrasound which looks at the neck of the developing fetus. The invasive methods for genetic testing are Chorionic Villus Sampling or Amniocentesis. Both these methods have a risk of miscarriage and both must be attempted after the non invasive methods. The non invasive methods are not 100% accurate but can suggest a higher chance of the syndrome. Therefore, the best method of testing is to use the non invasive method, followed up by an invasive method for confirmation. The invasive method should only be used if the non-invasive method provides a suspected positive result. The mother's age is also relevant in this case as older women tend to have a higher rate of Down Syndrome affected children.

More articles from the Genetic Testing Category