The Food and Drug Administration approved the first-ever direct-to-consumer genetic testing for people’s personal risk of contracting 10 potentially serious conditions including late-onset Alzheimer’s, Parkinson’s disease, celiac disease and a hereditary blood-clot condition called thrombophilia.

The product is offered by the closely held Silicon Valley genetics-testing company 23andMe Inc., which was initially stymied by the FDA in 2013 when it sought to offer such saliva-analysis tests to the general public. But the company began making more headway by 2015, when it offered consumers a test to tell them if they carried a genetic variant for one of 36 diseases that could be inherited by their children. Those hereditary tests evaluated people for their likelihood of passing on conditions like cystic fibrosis, sickle cell anemia and a disease known as Bloom syndrome.

To date, about two million people have purchased a test from 23andMe, which currently sells an ancestry test for $99 and a combined heredity and ancestry test for $199. With the FDA approval, customers of 23andMe will soon be able to get information about their own risk of 10 diseases, included in that $199 package. The company’s executives, in a phone interview, said that information about four of those diseases—also including a gene variant known as AAT deficiency that can lead to lung or liver disease—will be available by the end of this month, and others will be rolled out later.

The Mountain View, Calif., company stressed that, in all cases, the test “does not describe a person’s overall risk” of developing the disease in question, which can be affected by environmental factors and a person’s lifestyle.

“This is a very significant development,” said Jeffrey N. Gibbs, a medical-device attorney with the Washington, D.C., firm of Hyman, Phelps & McNamara who specializes in FDA matters. Now that this first approval for personal genetic tests has occurred, subsequent products can go through a simplified, and quicker, FDA process that simply requires a company to demonstrate it is substantially equivalent to the test already on the market.