Down Syndrome: Understanding the Condition

Down Syndrome was first clinically identified in 1866 by the Brittish doctor, John Langdon Down. This is a genetic condition caused by extra genes from the 21st chromosome. People with Down Syndrome have all of the other genes given to them by their parents. As a result, they have a combination of features typical of Down Syndrome on top of the individual features from their parents. This includes some degree of mental retardation, or cognitive disability, and other developmental delays. Some common physical traits are epicanthal folds over they eyes, flattened bridge of the nose, a single palmar crease, and decreased muscle tone. As it is unclear what causes the 21st chromosome, it is known that the 21st chromosome causes an extra dose of some proteins. Those proteins cause the typical features os Down Syndrome. It is also known that there is an association between a mother's age and the chances of having a baby with Down Syndrome.

There are 3 types of Down Syndrome. The first is called Trisomy 21. This is where the 21st chromosome pair does not split as it normally would, and a double-dose goes to the mother's egg. This is the most common type of Down Syndrome.
The second type is called translocation. Here, an extra part of the 21st chromosome gets stuck into another chromosome. Half of the time in these situations, one parent carries the extra 21st chromosome material in a hidden form.
The third type of Down Syndrome is referred to as mosaicism. This is not a very common form of Down Syndrome at all. In this type, the person has an extra 21st chromosome in only some of the cells, but not all of them.

There are two types of tests that may be done during pregnancy to help determine if a fetuse has Down Syndrome. One test is a diagnostic test, which is an amniocentesis and chorionic villus sampling (CVS). With an amniocentesis, a needle is passed through the mother's belly and into the womb to sample fetal cells in the amniotic fluid. The cells are then sent for chromosome analysis. An ultrasound is used to safely pass the needle. This test is usually done between 14 and 18 weeks of pregnancy. CVS samples cells from the chorionic villi, a structure in the womb that has fetal cells, but is not the fetus. This is normally done between 9 and 12 weeks of the pregnancy. Both of these tests are fairly safe, but there is a small risk of miscarriage with each of them.

Screening tests include maternal alpha-fetoprotein (AFP) and the triple test. The AFP test was originally devised to sreen for neural tube defects, such as spina bifida. A low level of AFP is correlated with Down Syndrome and some other chromosome disorders. The test is estimated to detect approximately 35% of fetuses with Down Syndrome after confirmation by amniocentesis. AFP tests often have false positive results and are usually optional for the mother to have done unless she is considered a high risk pregnancy. The triple test measures a mother's blood levels of himan chorionic gonadotropin (hCG), maternal serum alpha-fetoprotein, and unconjugated estriol. The three results are adjusted by a computer program to give an estimate of the risk of having a fetus with Down Syndrome. Because the accuracy of all of the serum tests depends on accurately knowing the number of weeks of pregnancy, a positive test should have an ultrasound done to confirm the due date of the pregnancy. If the adjusted test results are still positive, then either an amniocentesis or chorionic villus sampling should be done.

As the general life expectancy is reduced by ten or twenty years, some people with Down Syndrome have been known to live into their eighties. Just like we can not change our genetic make-up, we can not change the genetis make-up for a person with Down Syndrome. It can not be cured or out-grown. There have been proposed medical treatments, but none have been proven effective. These treatments have included thyroid hormones, pituitary extract, glutamic acid, dimthyl sulfoxide, Sicca cell therapy, five-hydroxytryptophan, various vitamin and mineral therapies and nootropic drugs such as piracetam. Sicca cell therapy has been shown by many reports to be dangerous and studies looking at the use of vitamin supplements showed no benefit.

Even though Down Syndrome has illnesses that may accompany it, people with Down Syndrome are still normal people. They have feelings just like anyone esle. They love to learn, play, and want to be accepted by others. They are very enthusiastic and reliable. If you know someone with Down Syndrome, take the time to offer a friendly word and smile to them, as it is likely they are or have been bullied through their lives. School can especially be hard for a child with Down Syndrome because they look differently, so many children may tease or bully them. People with Down Syndrome can be great friends and wonderful people like anyone else can. They deserve to be treated with as much respect as any other person.