Cri du chat in adults dating the origins of polyploidy events
Each chromosome can duplicate an exact copy of itself so that each new cell that is formed has a full, identical set of chromosomes.
Rarely, there is a problem with the child's chromosomes.
Possible problems include too many chromosomes, too few chromosomes or damage to one or more chromosomes.
The abnormal chromosomes may mean that the baby cannot survive and so may cause a miscarriage.
However, those babies severely affected may die within the first year of life.
Chromosomes are found in the centre (nucleus) of a cell.
New body cells are produced for growth and repair by cells dividing, producing two 'daughter' cells.
Each cell of your body contains chromosomes which are made up of many genes.