Genetic Disorders

Genetic tests are available and can reveal varying degrees of genetic information depending on the test. Most of these tests are performed by isolating chromosomes or by measuring a protein product that is excreted in the urine to test for biochemical defects. These tests can be used prior to conception to determine a couple's risk for having an affected child, during pregnancy, at birth or later in life.

The most successful wide-spread test for genetic disorders is the newborn program that tests for diseases such as PKU. Newborn screening for hypothyroidism and galactosemia are also performed in several states. Prenatal testing in embryos and fetuses include chorionic villus sampling (CVS), amniocentesis, and ultrasound. CVS can detect Down syndrome, hemophilia, DMD, CF, SCA, and sex chromosomal aberrations. Amniocentesis can detect Tay-Sachs disease, Down syndrome, hemophilia, spina bifida, and other abnormalities. Ultrasound is used to visualize the developing baby; it can detect spina bifida, anencephaly (no brain), and limb deformities.

Genetic counseling and testing can help people find out if they carry the gene for some disorders, or whether they will develop a late-onset genetic disorder themselves. Genetic probes can identify the genes for Huntington's disease, cystic fibrosis, Tay-Sachs, sickle-cell, thalassemia, and abnormalities associated with growth hormone. Genetic testing capabilities increase each year as additional genetic disorders are better characterized and the gene localization and protein function is determined.