Genetic Screening and Counselling

Genetic screening can be used to predict the possibility of a genetic disorder being passed from generation to generation. There are two main categories:
Pre-natal Screening
Amniocentesis involves the withdrawal of some amniotic fluid containing fetal cells at about eighteen weeks of pregnancy. A karyotype of the fetal chromosomes is made and this can be used to determine wether a child will have chromosomal abnormalities such as downs syndrome.
Chorionic Villus sampling is when a sample of placental tubes are taken using  into the mothers reproductive tract. The cells are then used for karyotyping as before.
Post-natal Screening
Phenylketonuria (PKU) can be tested for post birth by having blood tested for excess phenylalanine within the first few days of being born.