The causes of congenital abnormalities can be categorized into genetic factors, environmental factors, and multifactorial inheritance.
Genetic factors: These include abnormalities in the chromosomes or genes. Examples include Down syndrome, which is caused by an extra copy of chromosome 21, and cystic fibrosis, which is due to mutations in a specific gene. Environmental factors: These include maternal infections, exposure to harmful substances (such as drugs, alcohol, and certain medications), and poor maternal nutrition. For example, rubella infection during pregnancy can lead to congenital rubella syndrome. Multifactorial inheritance: This involves a combination of genetic and environmental factors. Examples include cleft lip and palate, and neural tube defects like spina bifida.
