Cri du chat in adults
One chromosome from each pair is inherited from your mother and the other is inherited from your father.
One of these chromosome pairs is known as the sex chromosomes because this pair determines our sex.
Cri du chat syndrome is a chromosome problem caused by a missing piece of chromosome 5.
'Genetic' means that the condition is passed on through families by special codes called genes.
The other 22 pairs of chromosomes are numbered according to size with 1 being the longest pair and 22 being the shortest pair of chromosomes.
However, egg and sperm cells only have 23 chromosomes (1 chromosme from each pair).
Females have two of the same kind of sex chromosome (XX). The Y chromosome contains the male determining genes.
So, a normal female is 46, XX and a normal male is 46, XY.
Each cell of your body contains chromosomes which are made up of many genes.