A new method enables researchers to test algorithms for spotting genes that contribute to a complex trait or condition, such as autism.

Researchers often study the genetics of complex traits using genome-wide association studies (GWAS). In these studies, scientists compare the genomes of people who have a condition with those of people without the condition, looking for genetic variants likely to contribute to the condition. These studies often require tens of thousands of people to yield statistically significant results.

GWAS have identified more than 100 genomic regions associated with schizophrenia, for example, and 12 linked to autism. Results are often difficult to interpret, however. Causal variants for a condition may be inherited with nearby sections of DNA that do not play a role.