What causes Down syndrome?

DOWN'S syndrome is a condition in which an individual inherits an extra copy of certain essential components from parents. Usually everyone is required to have just two of these components, however an individual with Down syndrome has three copies instead.

Features

A child with the condition generally has specific changes in the body or characteristic which can easily be identified. He/she has a reduced muscle tone. This is tension in muscles.

A baby born without the condition is usually not soft or floppy but has adequate tension in the muscles to lift arms and legs or have quick movements.

A baby with this condition has slow arm and leg movements and whenever you lift the child you would realize that you have to be extra caution to support the head and the entire body well otherwise it may look like the baby would slip out of your hand.

The low muscle tone is associated with a reduction in muscle strength and endurance, so the baby is easily tired when engaged in activities or play. This makes learning skills such as holding the head up to look around him, sitting independently, crawling etc much harder for the child.

Parents may also complain that the baby is difficult to handle during bath time, feeding, dressing up etc and this is due to the increased flexibility in the joints.

You may notice this especially in the shoulders and hips but as the child grows older and gains strength the risk of injury to those joints reduces.

The baby's movements are poorly coordinated as a result of these characteristics and it is required that they know the appropriate movement patterns to avoid unnecessary strain on the joints as they grow older.

A child with this condition also has a flattened nose, small ears and mouth and wide short arms and legs compared to the trunks or torso. This may make it more challenging when performing activities such as running or climbing as compared to their peers.

You may notice that the physical development of the child is slow as compared to others around the same age and the average height is also shorter as compared to his/her peers. Due to the feature that the children have they develop compensatory movements which may result in injuries.

For example the child has a tendency to walk with their feet wide apart with the feet turned outwards and locked or stiffened knees.

Most of the weight of the body is borne only in the inner aspect of the feet instead of being distributed over the entire foot. This inappropriate gait is as a result of having poor stability and weakness in the leds and over a period of time if not corrected the child develops problems with the knees and feet making walking painful eventually.

Physiotherapy is required early to prevent/minimize the child from developing this pattern of walking so that the feet are placed under the hips with the toes pointing forwards.

Risk factors

The precise cause of the condition is unknown and can occur in any family. It is not associated with anything the mother did before or whilst pregnant.

Some women may have an increased risk of having a child with the condition if they get pregnant when they are older.

Also the risk of having a child with Down syndrome is increased if you've previously had one who had the condition.

How is diagnosis made?

A number of tests can be performed during pregnancy and after the baby is born to confirm the diagnosis.

The physical features of the baby after birth as well as a test conducted to analyze the chromosomes (the essential components that each individual has) and find out if there is an extra chromosome 21, confirms diagnosis.