Most genetic testing requires a doctor's prescription. In April 2017, however, 
the U.S. Food and Drug Administration (FDA) gave genetics company 23andMe the 
go-ahead to sell DNA tests assessing the user's level of risk for ten health 
conditions, including Parkinson's disease and late-onset Alzheimer's disease. 
This was followed nearly a year later by approval to sell tests for three 
mutations in the genes BRCA1 and BRCA2 linked to increased breast cancer risk. 
These remain the only FDA-approved direct-to-consumer (DTC) tests for genetic 
risk of disease.