BELOW ARE some of the conditions for which genetic medical tests are being marketed to consumers over the Internet. Most involve testing cells from the cheek, stool or blood to determine whether they contain mutations of genes implicated in the development of various diseases.
In many cases, a positive test does not mean that a person will develop the disease, only that the lifetime risk is higher than normal. Geneticists emphasise that testing is not infallible: Tests produce false negatives and false positives, and it's important for consumers to ask about accuracy rates.
Cystic fibrosis, a hereditary disorder that attacks the lungs and other organs.
Factor II and V Leiden, inherited blood disorders that increase the risk of developing blood clots.
Hereditary hemochromatosis, an overload of iron in the blood.
BRCA 1 and 2, genes associated with increased risk of breast and ovarian cancer.
Celiac disease, an intestinal condition resulting from an inability to digest wheat products.
Alpha-1 antitrypsin deficiency, a liver protein shortage that can cause emphysema or cirrhosis.
Alzheimer's disease.
Colon cancer screening.
Other home DNA tests that have less scientific proof of validity include those to determine the sex of a foetus, nutritional status, skin care recommendations and susceptibility to depression.
Sources: Genetics and Public Policy Center, Johns Hopkins University; DNA Direct; Neuromark; Graceful Earth; Sciona; Health Tests Direct; Healthcheck USA.
- Los Angeles Times-Washington Post News Service
