What is Down syndrome?

Down syndrome is a genetic condition – it is not an illness or disease. It occurs as a result of an extra chromosome.
Our bodies are made up of millions of cells, and in each cell there are 23 pairs of chromosomes – or 46 chromosomes in every cell. Down syndrome is caused by the occurrence of an extra chromosome, chromosome 21 (Down syndrome is also known as trisomy 21). People with Down syndrome therefore have 47 chromosomes in their cells instead of 46. This results in a range of physical characteristics, health and development indications and some level of intellectual disability.

Down syndrome is usually recognisable at birth and confirmed by a blood test. It was named after Dr John Langdon Down who first described it. Although we know how Down syndrome occurs, we do not yet know why it happens. Down syndrome occurs at conception, across all ethnic and social groups and to parents of all ages. It is nobody’s fault. There is no cure and it does not go away.
Down syndrome is not a new phenomenon and cases have been recorded through history.Nor is it a particularly rare condition – Down syndrome is the most common chromosome disorder and one of every 700-900 babies born will have Down syndrome. This number has not altered significantly throughout the time that statistics have been collected.