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History of Down Syndrome and Useful Information

Submitted by Justin on Monday, 15 December 200810 Comments

Down Syndrome is the commonest identifiable cause of intellectual disability, accounting for around 15-20% of the intellectually disabled population.

It is believed that people with Down Syndrome have always existed. However, it was not until 1866 that the English doctor, John Langdon Down, first described the condition, which subsequently took his name.

History of Down’ Syndrome

In 1959 Professor Jerome Lejeune, a geneticist in Paris, discovered that Down Syndrome occurred as a result of a trisomy of chromosome 21. This means that instead of the usual 46 chromosomes in the cells of the body, there is an extra chromosome 21, making 47 chromosomes in all. Since then, other forms of the condition, which are much rarer, have been discovered, such as Translocation and Mosaicism. Approximately 94% of people with Down Syndrome have standard trisomy 21, 4% have a translocation and 2% mosaic Down Syndrome.

In the vast majority of cases, Down Syndrome is not hereditary.

What causes Down Syndrome?

As yet we do not know what causes the presence of an extra chromosome 21. It can come from either the mother or the father, but most commonly from the mother. There is no way of predicting whether a parent is more likely to produce an egg or sperm with 24 chromosomes. There is a definite link with advanced maternal age for reasons yet unknown. However, most babies with Down Syndrome are born to women under the age of 35, as younger women have higher fertility rates.

Nothing done before or during pregnancy can cause Down Syndrome. It occurs in all races, social classes and in all countries throughout the world. It can happen to anyone.

Incidence

For every 1,000 babies born in the UK, one will have Down Syndrome. This means that about 600 babies are born with Down Syndrome each year in the UK. Down Syndrome affects people of all ages, races, religious backgrounds and economic situations. It is estimated that there are around 60,000 people with Down Syndrome living in the UK, but since Down Syndrome has never been a notifiable condition, accurate figures are difficult to obtain.

How is Down Syndrome diagnosed?

The diagnosis of Down syndrome is usually made soon after the birth of the baby because of the baby’s appearance. There are many physical characteristics associated with the condition, which may lead a parent or midwife, or other medical professional, to suspect that the baby has Down syndrome.

Some of the features include:

  • Reduced muscle tone which results in hypotonia
  • A flat facial profile, flat nasal bridge, small nose
  • Eyes that slant upwards and outwards, often with a fold of skin that runs vertically between the lids at the inner corner of the eye (epicanthic fold)
  • A small mouth which makes the tongue seem slightly large
  • A big space between the first and second toe (sandal gap)
  • Broad hands with short fingers and a little finger that curves inwards. The palm may have only one crease across it (single palmar crease)
  • A below average birth weight and length at birth

Many of these features are found in the general population. Therefore a chromosome test (karyotype) would need to be carried out before a positive diagnosis could be made. This is done by analysing the chromosomes in the blood cells.

Do people with Down syndrome have medical problems?

Certain health problems are more common in people with Down syndrome than in the rest of the population. These include:

  • 40-50% of babies with Down syndrome are born with heart problems, many of which require heart surgery
  • A significant number of people with Down syndrome will have hearing and sight problems
  • Thyroid disorder
  • Poor immune system
  • Respiratory problems, coughs and colds
  • Obstructed gastrointestinal tract

However, with advances and increased access to medical care most of these problems are treatable. None of these problems is unique to people with Down syndrome - they also occur in the rest of the population.

It is also important to remember that some people with Down syndrome do not experience any health problems.

Advances in treatment and increased access to medical care have also meant that people with Down syndrome are living much longer. Life expectancy is now put at 60-65, and many people with Down syndrome live even longer.

How does Down syndrome affect development?

All people with Down syndrome will have some degree of intellectual disability. Children with Down syndrome do learn to walk, talk and be toilet trained but in general will meet these developmental milestones later than their non-disabled peers. There is a wide variation in ability in people with Down syndrome just as there is in the rest of the population.

Early intervention programmes which help in all areas of child development are now widespread. These programmes can include speech and physical therapy as well as home teaching programmes for the child and the family.

Children and adults with Down syndrome can and do continue to learn throughout their lives just like the rest of the population.

Fact or fiction?

Children with Down syndrome are only born to older parents?

Fiction: 80% of children with Down syndrome are born to women younger than 35. However, the likelihood of having a child with Down syndrome
does increase with the age of the mother.

Children with Down syndrome are always happy?

Fiction: People with Down syndrome have the same feelings and moods as everyone else.

People with Down syndrome cannot form relationships?

Fiction: People with Down syndrome are perfectly capable of forming all types of relationships with people they encounter in their lives, be it friendship, love or dislike.

People with Down syndrome cannot have children?

Fiction: Women with Down syndrome can and have had children. It has been recorded that two men with Down syndrome have become fathers. The information about fertility in people with Down syndrome is very outdated and based on research in institutions where men and women with intellectual disabilities were kept apart.

All people with Down syndrome will eventually develop Alzheimer’s disease (dementia)?

Fiction: Although many people with Down syndrome do develop dementia in their later years, this is by no means inevitable. Research indicates that the incidence of dementia in people with Down syndrome is similar to that of the general population only that it occurs 20-30 years earlier.

Further information can be obtained from “People with Down syndrome at all Ages” by S. Trumble, “The Genetics of Down Syndrome” by A. Kessling & M.Sawtell, and “The Immune System in Down Syndrome” by M.A. Kerr on this site and from the Down Syndrome Association website www.dsa-uk.com. We strongly recommend that you view these and the Down Syndrome Medical Interest Group website: www.dsmig.org.uk.

10 Comments »

  • macrina asmar said:

    I found this information useful. I am a Public Health Nurse and I found intriguing that a lot of first time young Hispanic moms were having babies with Down Syndrome. At this point it is just anecdotal based on the amount of reported cases to my area but they do seem to be on the increase. Are there any studies that indicate % of ethnicities?

  • Lois said:

    What kinds of problems can they have with their thyroid? What happens if not treated?

  • Jean Rolf said:

    I am a mother of a Down syndrome daughter born in 1950 (on my 22nd birthday). I became a member of the local and national ARC in 1953 and worked to educate the community on the retarded. And organized a pre-school class for 4 to 8 year olds. My daugher progressed well, the public school program was mostly geared to crafts and I believe my daughter could have learned much more. She lived at home with me until 1996, I am a widow. After a fall she went to a medical rehab facility in the area and receives good care.
    Now she appears to have Alzheimer’s and I don’t know how to cope with that. As her brother said, Susan was 90% happy and 10% stubborn and now it is reversed. She is mostly unhappy, concerned about her possessions. I would like to know what I can do to help her lead a happier life and what I can do to make her life better and for my piece of mind. What is the prognosis?
    I am currently a member of the county ARC group and the national ARC. I would appreciate a reply.
    Jean Rolf

  • silverwolf8 said:

    I work with a DS adult that is 45 yrs old & drs say his body is approx of a 75 yr old But he is very active … he loves to bowl & since his Dad passed away he rarely talks but he does talk tho … Any & all information about DS would be sooooo helpful

  • tysmom said:

    I have a question, I’m not sure if anyone will know the answer… I am a 21 yr old mom of a son with ds. After my son was born I found out that I have hypothyroidism so I started doing research on it and found that some studies show a link between that and having babies with ds. Does anyone know how accurate this is? I am young and still want to have more kids, but my fiance and I are afraid that if we did have another child with ds we might not be as fortunate medically speaking.

  • Justin (author) said:

    Hi Misty,

    Teddy also has a thyroid that works overtime. Our Dr. basically said that at some point it will “burn out” and then he will have to go on supplemental medication to even out his metabolism.. until then, he will probably be as skinny as a stick…You just need to pay attention to it with is Ped. going forward.

    Teddy was also our first (two other boys since). We had the same concerns as you about subsequent children but the geneticist assured us we didn’t have a hereditary predisposition. So, each subsequent child has the same odds as any other in your age bracket. Because you are so young, it is highly unlikely (although certainly possible).

    If you want to have more children, I suggest you think about it just as if your first child were “Typical” …I do think that you Son would appreciate a sibling :) The best advice of course is to speak with your Dr.

  • bernard said:

    Sorry I’m not much of a help. I’m just coming to terms with my son’s ds.

  • ghamma said:

    comment:
    Could anyone explain to me the definition of mosaic down syndrome and what evaluative tool is used to determine this syndrome.

  • Laura said:

    A study or mapping of the chromosomes is used to determine wether a person has mosaic down syndrome. Mosaicism means there is just an extra “piece” of a chromosome and not a whole extra chromosome. I think! A geneticist would be a good person to speak with about this matter. He/she would look at this “map” of the chromosomes which is obtained though a simple blood draw. I don’t know what the clinical manifestations (if any) are different between mosaic DS and the more typical DS.

  • aimebell said:

    Hi, I am new to this site. I am a Child Care Provider. I have a small daycare in home. No more than six children at a time. I also am a foster parent. I have cared for many children in the last 20 years. I am familiar with special needs from learning disabilities to drug exposed infants to fas. I will be caring for a child with Down Syndrome come fall. I am looking for tips to help him succeed. We are looking forward to having a baby around. Other than treating him as we would any baby that comes into care, should we add or adjust anything?
    Thanks

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