Down Syndrome - What are the Symptoms, Causes, Diagnosis, and Treatments?
Down syndrome is a chromosomal (i.e. genetic) condition which delays development in children. The condition is not curable, and affects people in different degrees of severity. Families of Down syndrome kids have to learn to manage the condition, but many Down syndrome children go on to live happy and fulfilled lives, achieving important development milestones and benefitting from the education and support they are given.
Causes Of Down Syndrome
Down syndrome begins at the embryonic stage of fetal development in the uterus. Normally, the embryo divides into cells which contain 23 pairs of chromosomes in their nuclei. In Down syndrome kids, the nucleus of each cell has 3 copies of the 21st chromosome, instead of the normal two. The risk of having a baby with Down syndrome increases with the mother's age.
Down Syndrome Symptoms
Down syndrome causes cognitive delays (i.e. slower learning capabilities) and increases a child's risk of experiencing certain medical problems.
The primary physical features of Down's syndrome include distinct facial characteristics (you can see these if you look for Down syndrome pictures on the net). Down syndrome kids tend to have eyes that slant slightly upwards and a face that's "flat" in appearance. Other physical symptoms include low muscle tone, and a single deep crease in the palm of the hand.
Down Syndrome Tests
Down syndrome symptoms can be identified in children at birth, but there are also tests for the condition which can be carried during the pregnancy and after the baby is born. There are two types of prenatal Down syndrome tests, screening tests and diagnostic tests.
Down Syndrome Screening
The screening test determines the probability that a fetus will be born with Down syndrome. It usually involves a blood test (the blood is taken from the mother) and an ultrasound exam. The results of this test are not always accurate.
The diagnostic Down syndrome test is nearly 100% accurate. There are two types of procedure - one is called amniocentesis and the other chorionic villus sampling (CVS).
Amniocentesis involves extracting a small amount of amniotic fluid from the amniotic sac surrounding the fetus, and testing its DNA to look for chromosomal abnormalities. This test is carried out usually in or around the 15th week of the pregnancy. There is a very small risk that this test will trigger a miscarriage.
CVS involves extracting a small amount of tissue from the placenta and checking it for chromosomal problems. This test is carried out usually between the 9th and the 11th week of the pregnancy.
Tests After Birth
If a baby has physical signs of Down syndrome at birth, a genetic test called a karyotype will be carried out to confirm whether or not he or she is indeed affected by the condition.
Mosaic Down Syndrome
Babies born with Mosaic Down syndrome have some normal healthy cells, and others which are affected by the defect of the 21st chromosome. This is why doctors often talk about percentages of affected cells when referring to Mosaic Down syndrome patients. Just like regular Down syndrome, the level of severity of the Mosaic version of the condition varies from patient to patient, however, in some cases, because fewer cells are affected, Mosaic Down syndrome kids have much milder symptoms and are less affected by Down syndrome-related problems.
Autism And Down Syndrome
According to Down syndrome statistics, an estimated 7% of Down syndrome kids are affected by autistic spectrum disorder too. Because of the existing developmental challenges presented by Down syndrome, it can be difficult to diagnose developmental issues related to autism in a Down syndrome child. Nevertheless, awareness is increasing in the medical world of the interaction of these two developmental conditions, and better support and treatments are being developed all the time.
Turner syndrome is another chromosomal condition affecting girls only. Instead of having the normal 2 X chromosomes for females, girls with Turner syndrome have 1 X chromosome, or are missing part of the second X chromosome.
Girls suffering from the condition are usually particularly short in height and have number of other physical characteristics which can cause self-esteem issues. These girls usually won't experience the normal developmental changes of puberty unless they receive medical help. They often suffer from particular medical problems and learning difficulties, and are almost certainly infertile.
Growth hormones and estrogen replacement therapy are the treatments used to help Turner syndrome patients live more normal lives.