What are the basic steps of genetic testing?
The term genetic testing is commonly used to describe two very different applications screening and diagnosis. Genetic screening tests are used to warn people about potential health problems and to indicate who might require a diagnostic test. Genetic diagnostic tests are precise techniques that determine the presence of genetic disease. The heel prick test performed on newborn babies is a common screening procedure. This involves taking a blood sample from a newborn and analysing it for the presence of chemicals associated with metabolic disorders, such as PKU (Phenylketonuria), a genetic disease due to a deficiency of the enzyme that breaks down the amino acid phenylalanine. Infants with abnormal results in the heel prick test are generally referred to more precise diagnostic testing. Diagnostic tests are a direct examination of an individual s DNA. Hundreds of diagnostic tests are already being used to pinpoint genetic defects and the extensive gene mapping efforts of the Human Geno
