Scientists say they’ve found a new way to help determine whether specific genetic abnormalities are likely to make people sick, a step toward avoiding a vexing uncertainty that can surround DNA test results.

Researchers used genetic engineering to create thousands of tiny variations in a gene linked to breast cancer, and tested each one in a lab to predict whether it would promote the disease if it appeared in a person.

When those predictions were checked against what scientists know about the BRCA1 gene, “we were very accurate,” said Lea Starita of the Brotman Baty Institute for Precision Medicine in Seattle.

The technique, which she and her colleagues hope to extend to other genes, is aimed at better understanding genetic testing. Sometimes tests reveal an abnormality in a gene linked to the disease, but nobody knows whether it’s hazardous. It’s called a “variant of uncertain significance,” or VUS.

Such a result can cause anxiety and worse: Experts talk about women who’ve had breasts removed after learning they had a VUS, only to find out years later that further research showed their variants were harmless.

The new work aimed to identify variants in the BRCA1 gene’s DNA code that keep it from working. Mutations that disable this gene greatly raise the risk of breast and ovarian cancer. Results were published by the journal Nature.

Results look promising for resolving VUS in BRCA1 when used along with other information, said Heidi Rehm of Boston’s Massachusetts General Hospital and the Broad Institute in Cambridge, Mass.