DNA contains information about a person’s traits or characters which are stored as genes. DNA makes up chromosomes, which are found in pairs. Humans have 46 chromosomes, half from our mother, half from our father. When there are abnormalities in the genes or chromosomes of a fetus, genetic disorders occur. It could lead to chromosomal abnormalities such as Down Syndrome, Patau Syndrome or Edwards Syndrome. The occurrence is random and there is no evidence it is hereditary or caused by environmental factors.