Facts About Down's Syndrome

Education programs before reaching school age may be useful. School-age children with Down syndrome may benefit from inclusive education (whereby students of differing abilities are placed in classes with their peers of the same age), provided some adjustments are made to the curriculum.

- Dr Arun Oommen

Down syndrome (trisomy of chromosome 21) is the most common chromosome abnormality in humans occurring in about one per 1000 babies born each year. It is typically associated with physical growth delays, characteristic facial and physical features, mild to moderate intellectual disability, poor immune function and an increased risk of a number of other health problems, including congenital heart disease, leukemia, thyroid disorders, and mental illness.

Risk factors for down's syndrome include:

• Advancing maternal age: A woman's chances of giving birth to a child with Down syndrome increases with age because older eggs have a greater risk of improper chromosome division. By age 35, a woman's risk of conceiving a child with Down syndrome is about 1 in 350. By age 40, the risk is about 1 in 100, and by age 45, the risk is about 1 in 30.

• Having had one child with Down syndrome risk for the next child with down syndrome is about 1 in 100.

• Mothers who have Down syndrome themselves are 50% more likely to give birth to a child with Down syndrome.

• Being carriers of the genetic translocation for Down syndrome: Parents can pass down a chromosomal abnormality called balanced translocation, which contributes to the Translocation Down syndrome. In this instance, the parent does not have signs of Down syndrome, but has genetic material "balanced" between chromosome 21 and another chromosome, posing an increased risk for the child if that material attaches to the other chromosome when the cell divides.

• Folate metabolism is abnormal in mothers of children with Down syndrome and that this may be explained, in part, by a mutation in the MTHFR gene.