Down's
Syndrome

Down's Syndrome originates in the genes. Every cell contains several chromosomes, and these tiny particles carry the blueprint for our inherited characteristics. These particles are the blueprint for all the characteristics that we inherit. Normally there are 46 chromosomes in every cell; half come from each parent. The person with Down's Syndrome has an extra chromosome 21 – making 47, disrupting the developing baby's growth.

This extra chromosome can come from either parent and is present because of a genetic accident when the egg or the sperm is made or during the initial cell division following conception.

The features include:

• Eyes that slant upwards and outwards. They often have a fold of skin that runs vertically between the two lids at the inner corner of the eye (the ‘epicanthic fold’).
• A head that is relatively flat at the back with a low hairline and ill-defined at the nape of the neck, often with rather loose skin in this area.
• A face that appears somewhat flat with a flat nasal bridge.
• The mouth cavity is slightly smaller than average, and the tongue is larger. The child’s tongue may thus protrude, a habit that can be stopped with teaching.
• Broad hands, with short fingers and a little finger that curves inwards. The palm may have only one crease across it.
• A deep cleft between the first and second toe extends as a long crease on the side of the foot.
• Reduced muscle tone, which results in floppiness (hypotonia). This often improves spontaneously as the child gets older, but some are left with a low tone posture, which may lead to normal Orthopaedic conditions later in life in the lower limbs, e.g. osteoarthritis.
• A below-average weight and length at birth.

It is essential to point out that any of these features can occur in people who do not have Down’s Syndrome. For example, 4%-5% of children who do not have Down’s Syndrome have a single crease across their palm; 6%-8% of children without Down’s Syndrome display epicanthic folds; and 25%-50% of people who do not have Down’s Syndrome have slanted eyes, flat back of the head, small ears and flat nasal bridge.