A new DNA test has recently been shown to determine a range of difficult-to-diagnose neuromuscular and neurological genetic diseases faster and more precisely than the existing tests today.
A EuerkAlert! report specified that according to Dr. Ira Deverson, Head of Genomics Technologies at the Garvan Institute of Medical Research and senior author of the study, they correctly diagnosed all patients who have conditions that were already known, which include Huntington's disease, hereditary cerebellar ataxias, fragile X syndrome, myoclonic epilepsies myotonic dystrophies and motor neuron disease, among others.
In this new research, researchers at the Garvan Institute in Sydney, together with collaborators from Australia, the United Kingdom, reported that the disease covered by the test was part of a class of more than 50 diseases caused by extraordinarily long repetitive DNA sequences in the genes of a person called "Short Tandem Repeat" or STR expansion disorders.
A 'Game-Changer'
Dr. Deveson explained they are frequently difficult to diagnose because of the multifaceted symptoms that patients report, the challenging nature of such repetitive sequences, as well as "limitations of existing genetic testing methods."
The new research recently published in the Science Advances journal shows that the test is precise, and it enables the team to start with its validations to make the test available in pathology services globally.
Joh, a patient who took part in the study, first realized something wrong when he experienced rare problems balancing while on a ski lesson.
He said, "It was very worrying having symptoms" that, through the years, increased in severity, from being active and mobile to being unable to walk minus support.
John, who was eventually diagnosed with a rare genetic illness known as CANVAS which affects the brain, went through test after test for more than a decade and absolutely no answers as to what the problem was.
According to Dr. Kishore Kumar, co-author of the study and clinical neurologist at the Concord Hospital, for patients like John, this new DNA test "will be a game-changer," helping put an end to what can frequently be a "taxing diagnostic odyssey."
The New DNA Test
Dr. Krumar explained this new test will revolutionize how such diseases are diagnosed since they can now test for all the disorders at once with just one DNA test and provide a clear genetic diagnosis, helping patients get rid of years of unessential nerve or muscle biopsies for diseases they don't have, or risky treatments that can defeat their immune system.
Even though repeat expansion disorders are incurable, a faster diagnosis can help doctors determine and treat disease complications ahead of time, like heart conditions linked to Friedreich's ataxia.
With a single DNA sample typically extracted from blood, the test works by scanning a patient's genome through the use of a technology known as Nanopore sequencing, a similar SciTechDaily report said.
Dr. Krumar said they've programmed a Nanopore device to hone in on the approximately 40 genes known to be involved with the said disorders and to read through the long, repeated DNA sequences which are causing disease.
By disentangling the two DNA strands, he continued explaining and reading the repeated letter sequences, particularly the combinations of A, T, G, or C; they can scan for unusually long repeats within the genes of patients, which are all the symbols of disease.
In a single test, elaborated Dr. Deveson, they can search for each known disease-causing repeat expansion sequence and possibly discover novel sequences potential to be involved in illnesses "that have not yet been described."
Report about the new DNA test is shown on The Study Finds Guy's YouTube video below:
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