New analysis of an old genetic test still often provides the diagnosis

People with a rare condition often have an error in their DNA that causes the disease. So doctors map their DNA using a technique called sequencing analysis. They use smart software to look for faulty genes. One third of patients are diagnosed. If that doesn’t work, the advice is: come back after a few years.

modern techniques

“Only half of the patients follow this advice and go to the hospital again,” says doctoral candidate Gabe Schuberts of Radbodomc’s Department of Genetics. “This is a shame, because we did a study that shows that after a few years, thanks to modern technologies, we can increase the number of diagnoses from a third to 53 percent.”

rapid developments

Together with pediatric neurologist Jolanda Schieving, Schobers has followed 150 children with neurological disorders, such as epilepsy. Schippers: “After the first test, 47 children were diagnosed immediately. We looked at all the other children again until five years after the test. Half of them reported themselves as advised, and the other half got a call. We did a new analysis on the old DNA measurements.” If we don’t find anything, we map the DNA again. So a total of 32 patients are still diagnosed.”

Researchers are finding more genetic errors because advances in genetics are moving at lightning speed. “We’ve already found some genes before, but only in recent years have they been linked to a specific condition,” explains Lysenka Visers, professor of translational genomics. “In addition, the new software detects more errors. The sequencing analysis technology has also been developed. Thanks to better chemicals, we can now visualize the hard-to-reach bits of DNA.”

Clarity at last

Although the diagnosis is not made until years later for some patients, it is still very valuable. “There are medical reasons for this. The diagnosis clarifies the cause of the patient’s problems and may provide options for treatment and support,” Schieving says. “But clarity is also good for the patient. We often get very grateful responses from parents of children who, after years of research, hear about the cause of the condition.”

In the absence of a diagnosis, researchers advise sounding the alarm again in time. Investigation: “Then we look at the patient again. Sometimes there are new indications of a particular condition. And then, thanks to a new analysis or DNA test, you may be able to identify the cause.” And what are we going to do with the half that has not yet been diagnosed? Visser: “Now we are testing a more comprehensive analysis, where we look not only at genes, but also at the intervening DNA. Hopefully soon we will find more causes of the disorders.”

By: National Care Guide