Down syndrome: What causes this congenital disorder, everything you need to know

New Delhi: The Supreme Court on Tuesday turned down a Maharashtra woman's plea seeking to abort 26-week foetus afflicted with down syndrome.

The apex court while refusing to allow the woman to abort also cited that there was no physical risk to the mother in continuation of pregnancy, as per the report of the medical board constituted to examine the 37-year-old woman.

Down syndrome, also known as Down's syndrome, is a genetic disorder which causes intellectual impairment and physical abnormalities. Although children with down syndrome are undoubtedly less intelligent, they are fine people. Here are a few things you need to learn about the congenital condition:

• Babies born with down syndrome have an extra chromosome 21. Normally, at the time of conception a baby inherits 46 chromosomes - 23 from the mother and 23 from the father. However, most people with down syndrome have an extra chromosome 21 - for a total of 47 chromosomes instead of 46. Having this extra genetic material causes changes in physical features and developmental delays.
• Scientists don't know exactly what causes down syndrome, but there are certain risk factors. A woman's risk of having a baby with down syndrome is high if -

      - She's age 35 or older

      - She has a brother or sister who has the condition

      - She has had a baby with down syndrome.

• Down syndrome can be identified during pregnancy by prenatal screening followed by diagnostic testing or after birth by direct observation and genetic testing.
• Most children with down syndrome have distinctive facial features – such as small chin, slanted eyes, small ears, small mouth. Other common features include - short neck, short arms and legs, low muscle tone and loose joints, extra space between big toe and second toe. Many children with down syndrome are also born with heart, intestine, ear, or breathing problems.
• There is no cure for down's syndrome, but education and proper care can help improve quality of life of children with the condition.

Down syndrome is one of the most common chromosome abnormalities in humans, occurring in about one per 1000 babies born each year.