More than Mom’s Mitochondria

 By  Guest Contributor Ms. Thompson

For those of us outside of the field, genetics usually triggers memories of high school biology. Learning about the differences between RNA and DNA and the double helix could be fascinating for some, while others are more interested in the genetic code they carry. 

Taosheng Huang, pediatrician and geneticist at Cincinnati Children’s Hospital Medical Center, was surprised when he received the test results from a four-year-old boy. Using modern DNA sequencing technologies, Huang and his colleagues discovered that the boy's blood contained paternal-inherited mitochondrial DNA.

After a repeated diagnostic test with a fresh sample of blood, Huang’s discovery broke barriers in human genetics and made a major contribution to the Human Genome Project.

In general, we are a genetic mix of both maternal and paternal DNA found in the nucleus of our cells. However, the nucleus is not the sole location for DNA; cells contain powerhouses called mitochondria that carry their own DNA. In all known animals, mitochondrial DNA is inherited by the mother only, which is used on occasion to trace maternal lineage back in time. The discovery of paternal-inherited DNA has raised questions on the rate of evolution and the effects of genetic mutations.