Patient-Specific DNA Sequencing Finally Paying Off

Scientists are finally unraveling enough of the mystery of
human DNA to help individual patients.

In the last few months, a couple of stories have come out that show the promise of the upcoming genetic revolution. In each case, doctors found a patient’s best treatment by looking at every last letter of that patient’s DNA.

In the first case, a young boy had all the hallmarks of an immune problem but there was no conclusive diagnosis. Without knowing for sure what was wrong, doctors weren’t comfortable treating the boy with a risky bone marrow transplant.

Then scientists sequenced the boy’s DNA. Lo and behold there was a never-before-seen mutation in a known gene. This nailed down the diagnosis of a potentially life-threatening form of irritable bowel disease (IBD).

The doctors went ahead with the bone marrow transplant. The boy not only survived the treatment, but his symptoms cleared up as well. He is now essentially cured because he had his DNA sequenced.

The second case involves a set of boy-girl twins. They suffer from a movement disorder called dopamine-responsive dystonia (DRD).

Patients with DRD are usually treated with L-dopa. This can often clear up most symptoms but didn’t seem to help these twins as much. In particular, the twin sister still suffered severe enough symptoms to greatly diminish her quality of life.

Scientists sequenced the twins’ DNA and found out that they had a kind of DRD that responds best to both L-dopa and a medicine called 5-HTP. Once they both received this new treatment, their symptoms improved dramatically.

For example, the girl used to suffer from something called layngospasms that usually ended in vomiting. With the new treatment, this went away. An obvious improvement to her life!

Assuming prices keep dropping for sequencing and Congress keeps allocating money for basic research, there may come a day in the not too distant future when many more patients like these will be helped. People will have better lives because doctors can figure out what is wrong by looking at their DNA. As long as doctors have the tools they need to help patients that is.

Right now the information is so scattered and so specialized that most doctors can’t help without a scientist’s intervention. This greatly limits the number of patients who can be helped.

Getting this whole process streamlined enough so that more than just the wealthy, connected, or lucky can benefit won’t be easy. We need to generate lots more data. But we also need to collect and organize the data so doctors can take a patient’s DNA data and translate it into the right treatment without the help of a genetic scientist.

This last part is not exciting work but is absolutely necessary if the promise of the genomic revolution is to be fully realized. Here’s hoping someone funds something like this.

Great story about DRD and how L-dopa can help.

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