Down syndrome was named after John Langdon Haydon Down, a British physician and advocate of education for the mentally retarded, who first described it in 1866. In 1959, the French pediatrician Jerome Lejeune discovered that the disorder is caused by a chromosomal abnormality. Ninety-five percent of individuals with Down syndrome have Trisomy 21, an extra chromosome in the 21st pair (altogether, they have 47 chromosomes instead of the normal 46); four percent have translocation, a chromosomal abnormality; and one percent have mosaicism. Down syndrome is characterized primarily by varying degrees of mental and motor retardation. Most people with the disorder are retarded. Individuals with Down syndrome have IQs ranging from 20 to more than 90, with the mean being 49. They are also prone to possible heart defects, poor vision and hearing, cataracts, and a low resistance to respiratory infections. Until the discovery of antibiotics, most Down syndrome children died of pneumonia before reaching adulthood. People with Down syndrome are 20 times more likely than the general population to develop leukemia and a neurological condition similar to Alzheimer’s disease.
Individuals with Down syndrome have a distinctive physical appearance characterized by almond-shaped eyes (on which the condition’s former alternate name-mongolism-was based); a short, stocky build; a flat nose and large, protruding tongue (which makes normal speech difficult); a small skull flattened in the back; a short neck with extra skin; and small hands with short fingers. Other features include a fold of skin on the inner side of the eye; speckling at the edge of the iris; and a small amount of facial and body hair. Muscle tone is often poor, and newborns are prone to hypotonia, or “floppiness.” People with Down syndrome are widely recognized to have docile temperaments; and are generally cheerful, cooperative, affectionate, and relaxed, although there are no scientific studies to confirm this. Their motor, speech, and sexual development is delayed, and their cognitive development may not peak until the age of 30 or 40. In infancy, speech development is delayed by about seven months.
Recent research has led to the conclusion that Down children are capable of expressing complex feelings, of developing richer personalities, and of mastering higher degrees of learning using adaptive strategies (such as computer-aided learning to teach reading and writing). One developmental program that began with Down children as young as 30 months old and stressed positive parent-child communication eventually enabled the children to read at a second-grade level. The theory is that early stimulation helps to develop connections in the brain that might otherwise not have developed.
Although most people with Down syndrome were institutionalized until the 1970s, those with only moderate retardation are capable of achieving some degree of self-sufficiency. Today, with changed social attitudes and expanded educational opportunities, many lead productive, fulfilling lives. In less than a century, the expected lifespan of a person with Down syndrome has increased from nine years of age in 1910 to 19 or 20 after the discovery of antibiotics to age 55 today, due to recent advancements in clinical treatment.
More than 350,000 people in the United States have Down syndrome; one baby is born with Down syndrome for every 800 to 1,000 births in the U.S. Down syndrome babies are found in every ethnic group and socioeconomic class. About 5,000 babies are born yearly in the United States with Down syndrome. Twenty to 25 percent of children conceived with Down syndrome survive beyond birth. Women over age 35 have a one in 400 chance of conceiving a child with Down syndrome. For women age 40, the incidence becomes one in 110. For mothers age 45, the incidence increases to one child in every 35. Under age 30, women give birth to Down syndrome babies at a rate of one for every 1,500 babies born. However, women under age 35 actually bear 80 percent of Down infants, and recent studies suggest that the father’s age may play a role as well. Prenatal detection of Down syndrome is possible through amniocentesis and chorionic villus sampling and is recommended for pregnant women over the age of 35.
Further Reading
For Your Information
- Cicchetti, D. and M. Beeghly, eds. Children with Down Syndrome: A Developmental Perspective. New York: Cambridge University Press, 1990.
- Cunningham, C. Understanding Down Syndrome: An Introduction for Parents. Cambridge, MA: Brookline Books, 1996.
Further Information
- National Down Syndrome Congress, 1800 Dempster Street, Park Ridge, Illinois 60068-1146; Toll-free:(708) 823-7550; Phone:(800) 232-NDSC
- National Down Syndrome Society, 666 Broadway, New York, New York 10012; Toll-free:(212) 460-9330; Phone:(800) 221-4602
Gale Encyclopedia of Psychology, 2nd ed. Gale Group, 2001.
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THE Japanese yen weakened to a 20-month low (123.44) against the US dollar
and was headed for a fifth losing week on concerns that the Japanese
Government’s economic stimulus plan will not do much to fend off
recession. Policy leaders of the three parties in Japan’s ruling coalition
unveiled economic stimulus proposals that included steps aimed at speeding
up disposal of bad loans, boosting real estate sales and urging the Bank
of Japan to inject more capital into the banking system by buying more
long-term government bonds on the market.
The other world economies also reported slowdowns in their latest sets
of economic figures. Switzerland’s economy expanded at the slowest rate
since the first quarter of 1999, as growth in spending by companies
(particularly on construction) and consumers eased. Europe’s seventh-
largest economy grew an annualised 1.8 per cent from a revised 1.9 per
cent in the third quarter, the government said. From a year earlier,
growth was 2.5 per cent, down from 3.6 per cent. The fourth quarterly
decline increases the likelihood of the Swiss National Bank lowering
interest rates soon. Switzerland would suffer from a pronounced slowdown
in the US and Europe, as more than three-quarters of its exports of
machine tools and chemicals are sold there.
On the Asian front, Korean industrial production increased in January
2001 (after a four-month decline) and the monthly trade surplus doubled.
Despite this, there is plenty of evidence the economy is still ailing.
Factories used just 74 per cent of their capacity in January (a 21- month
low) and inventories rose, suggesting companies are making more goods than
they can sell. The number of jobless people jumped 10 per cent in January
and many companies have put hiring on hold. More interest rate cuts are
needed to keep the economy from stalling, some economists said. Growth is
set to slow this year to 4 per cent from an estimated 9 per cent in 2000,
according to government estimates.
Technical Readings
Australia All Ordinaries (All Ords) (3,197, March 16, 2001) - Its key
support areas are located at 2,883, 2,951 and 3,120, whilst its resistance
areas of 3,219, 3,313 and 3,343 (its all-time high) look to cap the All
Ord’s rise. We favour a test of the support areas for the All Ords, whilst
selling at the resistance areas is expected to cap this very strong global
index. Its outlook is slightly lower and the market would expect the All
Ords to head down to its immediate support areas. Its technical readings
display significant bearish divergence, indicating waning upside strength.
French CAC Index (CAC) (5,104, March 16, 2001) - Its key support areas
are located at 4,452, 4,773 and 4,965, whilst its resistance areas of
5,155, 6,459 and 6,944 (its all time high) look to cap CAC’s rise. We
favour a test of the support areas for CAC, whilst selling at the
resistance areas is expected to cap this European stock. Its outlook is
very weak and the market would expect CAC to head down to its 3,773, 4,150
and 4,704 target areas. There is much more downside for this index.
German DAX Index (DAX) (5,734, March 16, 2001) - Its key support areas
are located at 4,948, 5,301 and 5,509, whilst its resistance areas of
5,935, 7,185 and 8,136 (its all time high) look to cap DAX’s rise. We
favour a test of the support areas for DAX, whilst selling at the
resistance areas is expected to cap this European stock. Its outlook is
very weak and the market would expect DAX to head down to its 4,360, 5,440
and 5,660 target areas. There is much more downside for this index.
UK Financial Times Index (FTSE) (5,562, Mar 16, 2001) - Its key support
areas are located at 4,949, 5,282 and 5,377, whilst its resistance areas
of 5,729, 6,514 and 6,950 (its all time high) look to cap FTSE’s rise. We
favour a test of the support areas for FTSE, whilst selling at the
resistance areas is expected to cap this European stock. Its outlook is
very weak and the market would expect FTSE to head down to its 4,950,
5,283 and 5,387 target areas. There is much more downside for this index.
HK Hang Seng Index (HSI) (13,522, Mar 16, 2001) - Its key support areas
are located at 10,979, 12,066 and 13,283, whilst its resistance areas of
13,616, 16,274 and 18,397 (its all time high) look to cap HSI’s rise. We
favour a test of the support areas for HSI, whilst selling at the
resistance areas is expected to cap this Asian stock. Its outlook is very
weak and the market would expect HSI to head down to its 9,917, 11,835 and
12,325 target areas. There is much more downside for this index.
Nikkei 225 Index (Nikkei) (12,232, March 16, 2001) - Its key support
areas are located at 9,703, 10,458 and 11,433, whilst its resistance areas
of 12,787, 14,186 and 17,661 (its July 2000 high) look to cap Nikkei’s
rise. We favour a strong test of the support areas for Nikkei, whilst
selling at the resistance areas is expected to cap this Asian stock. Its
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