New Finding Has Major Implications for Genetic Testing as Researchers Learn that Greater Numbers of Humans Have Multiple Personal Genomes

Here is a human genome curve ball for pathologists and clinical laboratory scientists engaged in genetic testing in their medical laboratories. New research indicates that a larger number of humans than was once believed may have more than one genome. This has implications for many medical and health issues.

Until recently, scientists assumed that, as a rule, each individual had a unique genome. Conditions such as mosaicism and chimerism were considered a rarity.

Greater Incidence of Multiple Genomes in a Single Individual

Now, however, different research studies are producing data that indicate a large proportion of humans may have more than one genome. This research has been enabled by advancements in both gene sequencing technology and the capabilities in computational and analytical software.

Chromosomal mosaicism exists when an individual has two or more cell populations with a different chromosomal makeup, according to the National Institutes of Health website. In cellular chimerism, two or more cell populations of different chromosomal constitutions—that are derived from different individuals—occur in a single individual.

Gene Sequencing of Larger Numbers of Patients

“[T]hree years ago...