The complete genome

Hereditary nervous diseases were proposed to be detected by genome-wide sequencing

Anastasia Kuznetsova-Fantoni, N+1

Neurologists from the UK and the USA conducted genome-wide DNA sequencing of 404 people to understand how successfully neurological diseases caused by repeats in the sequence of nucleotides in DNA can be diagnosed.

The method proved to be very effective with a sensitivity of 97.3 percent and a specificity of 99.6 percent. Genome-wide sequencing can help to quickly diagnose those people who do not have a family history of the disease or have non-specific symptoms. The study was published in The Lancet Neurology (Ibañez et al., Whole genome sequencing for the diagnosis of neurological repeat expansion disorders in the UK: a retrospective diagnostic accuracy and prospective clinical validation study).

Some hereditary diseases, such as Huntington's chorea or brittle X-chromosome syndrome, occur due to the expansion of repetitive sequences in different genes, which disrupts the synthesis of proteins that these genes encode. Such diseases are relatively common: one in 3,000 people. Usually, the diagnosis of these diseases is delayed for many years, as patients are offered a variety of genetic tests in which each gene is examined separately. The situation is even more complicated with those who have blurred or atypical symptoms of the disease — it is not always possible to suspect a "breakdown" of a particular gene in them.

Neurologists from the UK and the USA, led by Arianna Tucci from Queen Mary University of London, tested how applicable the method of genome-wide sequencing is in the diagnosis of diseases associated with the expansion of repetitive sequences. In this method, the DNA sequence of the patient is compared with the DNA of a healthy person to find repeats. The scientists obtained DNA samples of 404 people from the National Health Service, for whom the results of PCR testing for individual genes and the final diagnosis were also available.

Geneticists then performed genome-wide sequencing of the samples and learned that the method could detect the disease with a sensitivity of 97.3 percent and with a specificity of 99.6 percent.

At the next stage, doctors examined samples of 11631 people without diagnosed genetic pathologies by genome-wide sequencing and diagnosed 68 patients. Interestingly, among them were six children with nonspecific symptoms and without a family history of the disease, that is, their disease had a high chance of remaining undiagnosed.

Doctors recognize that a diagnosis is not a treatment, and patients will have to continue to live with the disease, but the method of genome—wide sequencing can significantly reduce the pool of tests they need to undergo, and in some cases slow down the progression of the disease. In addition, a genetic disease can also be suspected in relatives of patients and testing can be prescribed.

Neurologists are trying to find a cure for Huntington's disease. For example, they test molecules that bind simultaneously with the mutant protein gantingtin and proteins in the autophagosomes, thus directing the protein to cleavage.

Portal "Eternal youth" http://vechnayamolodost.ru