Using Whole Genome Sequencing to Diagnose Disease

A brief commentary written by Teri Manolio and Eric Green of the National Human Genome Research Institute at the National Institutes of Health (NIH) notes that whole genome sequencing technology is exciting in what it promises for improving diagnosis and care for individuals with genetic conditions, but more research would improve the use of whole genome sequencing to diagnose genetic conditions.

Just recently in the fall of 2013, the genes involved in Retinitis Pigmentosa and Prader Willi syndrome were identified with the help of whole genome sequencing. These discoveries do not automatically lead to a diagnostic test, but these examples show that whole genome sequencing is a promising tool in genetics research. There are also instances of scientists who have been able to use whole genome sequencing to determine a better course of treatment for an individual with a rare and undiagnosed condition.

Take for example the case of Nic Volker, who is often described as the first child saved by whole genome sequencing. Nic started showing severe intestinal disease symptoms at the age of two. For two devastating years, doctors could not figure out what was causing the problems, and Nic’s condition continued to get worse. At the time, whole genome sequencing was truly only being used in research and had not yet entered the clinical setting at all. Nic’s pediatrician contacted researchers that were studying whole genome sequencing, and a team agreed to take on Nic’s case. They sequenced Nic’s DNA and compared his DNA with the whole genome of a healthy human as well as the genomes of several other animals, including a fruit fly. They discovered that a single gene mutation or SNP was causing Nic’s severe illness, and from this knowledge were able to come up with a treatment plan that saved his life.

While the case of Nic Volker did thankfully have an amazing ending, this is not true of all cases that utilize whole genome sequencing. The results of whole genome sequencing may find a mutation that is causing the symptoms, but this may not indicate a better treatment plan or cure. Other times, scientists are unable to identify a mutation or mutations that seem to be causing the symptoms. This technology is certainly exciting and hopefully has great promise, but research has a ways to go before whole genome sequencing can be reliably used for improving treatments and patient care.

More Resources:
To read the full commentary from Teri Manolio and Eric Green, click here.

Read about the different ways Baylor College of Medicine is using whole genome and whole exome sequencing in the clinic:

These two videos below show examples of very lucky individuals whose doctors were able to successfully use whole genome sequencing to find the cause and a treatment for their symptoms.

Watch these videos to learn more about Nic and the miraculous science that save his life.

This video shows the story of Shelby, a little girl whose life was also saved by whole genome sequencing.