In the past year, several direct-to-consumer genetic tests have been introduced to capitalize on the falling cost of genomic technologies and the flood of studies linking genetic variants to disease. The tests generally use two technologies: microarray analysis, which searches the genome for specific genetic variations, such as single-nucleotide polymorphisms (SNPs), linked to disease or ancestral groups; and sequencing, which reads a DNA molecule letter by letter. Getting your genome examined is great fun. But the understanding of ancestry is still evolving. And broad genetic screening hasn't been tested for its clinical utility.