A mother's age at her child's birth is the only factor linked to the risk of having a baby with Down syndrome. This risk increases with each year of age, especially after age 35. But younger women are more likely to have babies than older women. So most babies with Down syndrome are born to women younger than 35.
About 95 percent of the time, Down syndrome is caused by trisomy 21 — the person has three copies of chromosome 21, instead of the usual two copies, in all cells. This is caused by abnormal cell division during the development of the sperm cell or the egg cell.
These factors include geographic region, maternal education, marital status, and Hispanic ethnicity. Because the likelihood that an egg will contain an extra copy of chromosome 21 increases significantly as a woman ages, older women are much more likely than younger women to give birth to an infant with Down syndrome.
It occurs because either the egg or the sperm involved in the formation of the embryo carried an extra copy of Chromosome 21. The vast majority of cases (about 90%) of Down syndrome are due to a problem with the egg. A small percentage of all eggs (and sperm) have abnormal chromosome arrangements.
Most cases of Down syndrome result from trisomy 21 , which means each cell in the body has three copies of chromosome 21 instead of the usual two copies.
If the screening test shows that the chance of the baby having Down's syndrome, Edwards' syndrome or Patau's syndrome is higher than 1 in 150 – that is, anywhere between 1 in 2 and 1 in 150 – this is called a higher-chance result. Fewer than 1 in 20 results will be higher chance.
There is nothing you can do to prevent or avoid your child having Down syndrome. However, your risk is lower if you have children at a younger age.
There is currently no way to prevent or cure Down syndrome. Prenatal testing allows you and your family to make informed decisions, including ending the pregnancy. For this reason, before you have the test it's a good idea to think about why you are choosing to do it, and how you will feel once you get the results.
Down's syndrome can be traced through families in less than 1% of people with the condition. These people all have rare types of translocation. It is very unusual for parents to have more than one child with Down's syndrome, or for relatives of these parents to have a child with the condition.
The rate of Down syndrome for both maternal and paternal age greater than 40 years is approximately 60 per 10,000 births, which is a six-fold increase compared with maternal and paternal ages less than 35 years of age. In this age group, the paternal contribution to Down syndrome was 50 percent.
In a sample of 75 children with trisomy for chromosome 21, or Down syndrome, there were 42 males and 33 females. The sex ratio was 1.30 which is statistically not significant (p greater than 0.05).
“We are presently studying whether stress can be directly linked to the down syndrome. Our observations do seem to suggest that stress is a factor which can play a significant role and we are collecting evidence to prove it.
As for any pregnancy reduced fetal movements are a sign of the fetus being in poor condition and should not be accepted as “typical for a baby with Down's syndrome.” Mothers need to be reminded that babies should remain active even during late pregnancy and to report any reduction in fetal movements.
In most cases of Down syndrome, a child gets an extra chromosome 21 — for a total of 47 chromosomes instead of 46. Rarely, the extra chromosome 21 attaches to another chromosome. This extra genetic material causes the physical features and developmental delays in people with Down syndrome.
In the majority of cases, the extra copy of chromosome 21 comes from the mother in the egg. In a small percentage (less than 5%) of cases, the extra copy of chromosome 21 comes from the father through the sperm. In the remaining cases, the error occurs after fertilization, as the embryo grows.
If a woman is a carrier for a balanced translocation that includes chromosome 21, then each of her children has about a 1 in 8 or 12% chance for ending up with Down syndrome. If a man is a carrier, this falls to around 3 in 100 or 3%. Scientists aren't really sure why there is a difference between men and women.
There is no definitive scientific research that indicates that Down syndrome is caused by environmental factors or the parents' activities before or during pregnancy. The additional partial or full copy of the 21st chromosome which causes Down syndrome can originate from either parent.
But Down Syndrome itself is neither dominant nor recessive. Trisomy 21 is an extra copy of chromosome 21. The idea of dominant versus recessive is not the correct lens to understand this condition because we are not talking about genes being passed down.
Foods with folic acid include : okra, pinto beans, navy beans, mustard green s, kale, spinach, chicken liver, beef liver, orange juice, asparagus, broccoli, avocado, green peas, cauliflower, tomato juice, peanuts, and cantaloupe.
Current supplementation policies designed to prevent neural tube defects may incidentally prevent Down's syndrome, provided a sufficiently high dose of folic acid is used.
People with Down syndrome can expect to live to 60
In the 1940s, a child with Down syndrome had a life expectancy of 12 years. These days, their life expectancy is 60 years and a baby born with Down syndrome could live into their 80s — in line with the general population.
An adequate intake of folic acid during pregnancy, believed to protect against neural tube defects (NTDs) in babies, may also help prevent Down's syndrome, researchers report in The Lancet this week.
There is no single, standard treatment for Down syndrome. Treatments are based on each person's physical and intellectual needs, strengths, and limitations. Services early in life focus on helping children with Down syndrome develop to their full potential.
Screening for Down syndrome can be performed as early as 11 to 14 weeks of pregnancy with a first trimester ultrasound and blood test. Screening can also be performed between 15 and 20 weeks by a blood test referred to as the multiple marker serum screening test.