The incidence of Down's Syndrome (DS) among Emiratis in Dubai is 1 in every 320 births (1:319), higher than the world average of 1 in every 800 births, according to data released by the Centre for Arab Genomic Studies (CAGS) – March 2013.
The figures point to the widespread practice of marriages between relatives, increased maternal age and high number of children to explain the higher incidence of DS compared to international figures. The relative risk for closely related parents to have babies with DS was four-fold higher than that for unrelated parents, according to the data.
It is unclear why the presence of an extra chromosome no. 21 occurs, but it can come from either the mother or father, however it is important to remember that it is no one’s ‘fault’ and nothing could have been done differently to prevent it happening. Down Syndrome occurs in all races, in all social classes and in all countries throughout the world. It can happen to anyone.
There are three type of Down Syndrome:
- Trisomy 21 is the most common and accounts for about 95 percent of all cases. An extra chromosome gets replicated in every cell of the developing body.
- Translocation accounts for about 3 percent of Down Syndrome cases. Here, the child is born with the usual 46 chromosomes but has a copy of chromosome 21 that attaches to another chromosome within the cell.
- Mosaicism makes up about 2 percent of Down Syndrome cases. Babies born with this type of Down syndrome have some cells containing 46 chromosomes and some containing 47, resulting in fewer and less-severe symptoms.
Although people have negative preconceptions about what it means for someone to have Down Syndrome, many of those living with the condition grow up to lead long and fulfilling semi-independent lives - read more about this in 6 common myths about Down Syndrome. It is also important to acknowledge that although non-invasive prenatal testing for Down Syndrome is now widely available, even a positive diagnosis is only for suspected Down Syndrome - there is still a margin of error in the diagnosis, and it's possible to have a false positive.