prenatal screening
Consultations with human geneticists and genetic counselors are an important first step in genetic testing. They will most likely prescribe some sort of prenatal screening see the Human Genetics: Diagnosis and Treatment Advanced concept . Prenatal screening also known as prenatal diagnosis or prenatal testing is the testing for diseases or conditions in a fetus or embryo before it is born. Methods may involve amniocentesis or chorionic villus sampling to remove fetal cells. DNA can be isolated from these cells and analyzed. If the mutation that results in the phenotype is known, that specific base can be analyzed, either through restriction fragment length polymorphism analysis or, more likely, through PCR and DNA sequence analysis. As it is the babys DNA that is being analyzed, the analysis will determine if the developing baby will have the mutation and develop the phenotype, or not have the mutation. Parents can then be informed of the probability of the baby developing the disease.