How Many People Have Down Syndrome ?
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Down syndrome is one of the most prevalent genetic disorders in the human race. It is a consequence of an altered genetic configuration in the form of occurrence of triple 21 chromosomes. The presence of this additional 21st chromosome leads to unusual physical features and retarded mental growth.
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Although the exact cause of the condition is yet to be discovered but many believe that the syndrome is the result of an arbitrary error in the egg of the mother. This is one of the reasons why the abnormality is often linked to the age of the mother, the probability of the condition being directly proportional to the increase in maternal age. Approximately 4 to 5 percent of such children are born to those having a family history of the disorder. This form of the disorder is termed as Translocation Down Syndrome. On the other hand, Mosaic Down Syndrome found in about 1 percent cases is the moderate variant of the disorder due to the presence of normal and trisomy cells.
Across the globe, a total of 5.8 million people are known to suffer from this chromosomal defect. About 1 in every 800 children in the United States is known to be born with Down syndrome. This ratio is equivalent to about 0.12 percentage of the population that is 340,000 numbers of people. The ratio in the United Kingdom for the same is 23.81 per 1000 births. Statistics furnished by the University of Ulster project 40 cases of Down syndrome being born in UK in the year 2002, while in the same year 26 abortions were deliberately conducted owing to prenatal detection of the abnormality. The risk of conceiving a fetus with Down syndrome is higher in older women. While the ratio is 1:1000 in women below the age of 30 years, it rises drastically to the level of 1:25 in women over 45.
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