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What’s driving progress in precision neurology?

Written by Sano Marketing Team | Nov 15, 2024 8:16:23 PM

Precision medicine is transforming neurology by enabling more accurate diagnoses and tailored treatments. Here, we explore key components driving this progress, including biomarkers, advances in genomic sequencing, and other critical areas of research.

Role of biomarkers in neurology

There are several kinds of biomarkers used in neurology:

  • Molecular biomarkers: These include DNA, RNA, and proteins that can indicate genetic mutations, gene expression levels, or protein presence related to specific neurological conditions.
  • Imaging biomarkers: Techniques such as magnetic resonance imaging (MRI), positron emission tomography (PET), and computed tomography (CT) scans can reveal structural and functional changes in the brain associated with different disorders.
  • Biochemical biomarkers: These involve the measurement of specific chemicals or metabolites in blood, cerebrospinal fluid, or other body fluids that can indicate disease processes.
  • Electrophysiological biomarkers: These include electroencephalography (EEG) and magnetoencephalography (MEG), which measure electrical activity in the brain to diagnose and monitor conditions like epilepsy and other neurological disorders.
  • Clinical biomarkers: These involve observable signs and symptoms or clinical test results that correlate with disease presence or progression.

Biomarkers are a key part of precision medicine, particularly in neurology. They are critical for identifying subtypes of neurological disorders and for understanding disease progression. For example, the presence of specific proteins in cerebrospinal fluid can indicate the onset of Alzheimer's disease long before clinical symptoms appear, allowing for earlier intervention. Similarly, genetic variants can predict susceptibility to conditions like epilepsy, meaning that preventive measures can be taken or proactive treatments administered.9 In addition to these examples, biomarkers can also guide treatment decisions, monitor therapeutic responses, and predict patient outcomes, making them invaluable tools in the management of neurological diseases.

Advances in genomic sequencing and diagnostics

Neurology has significantly benefited from advances in genomic sequencing and diagnostics, which can provide detailed insights into the genetic underpinnings of brain disorders. Techniques like whole-exome sequencing focus on the protein-coding regions of the genome, which, though comprising only about 1% of the entire genome, contain approximately 85% of known disease-causing variants. This concentration of variants highlights the exome's importance in genetic diagnostics, though it's worth noting that this figure may be influenced by selection bias. This method is instrumental in diagnosing rare genetic disorders and tailoring specific treatments that target these mutations.

Sequencing technologies currently used to enhance precision diagnosis and treatment development include:

  • Whole-genome sequencing: Analyzes the entire DNA sequence of an individual’s genome, providing insights into both coding and non-coding regions that can reveal genetic variants linked to health, disease, and genetic ancestry
  • Whole-exome sequencing: Focuses on protein-coding regions (exons) of the genome. It is faster than whole genome sequencing but does not capture variations in non-coding DNA; this misses key regulatory elements that play significant roles in gene expression and disease.
  • SNP genotyping: Targets specific genetic loci where single base pair changes, known as Single Nucleotide Polymorphisms (SNPs), are associated with certain traits. It is cheaper and faster than whole genome sequencing but provides limited information.
  • RNA sequencing: Analyzes complementary DNA of mRNA molecules in tissues or single cells to understand gene expression, offering insights into cell function.

Epigenetics in neurology

Epigenetic changes can influence gene expression without altering the DNA sequence, and can play a significant role in neurological conditions. These changes can be triggered by environmental factors, lifestyle, or disease states, affecting how genes are turned on or off. Understanding these modifications provides new insights into disease mechanisms and potential therapeutic targets. The best-studied example here is studies of DNA methylation: it has been found that hypermethylation of the APP gene promoter region has been associated with the early stages of Alzheimer’s disease. Detecting this epigenetic change can aid in early diagnosis and intervention.

Pharmacogenomics

Pharmacogenomics uses genetic information to predict how patients will respond to drugs, enhancing treatment efficacy and safety. By understanding the genetic factors that influence drug metabolism and response, clinicians can select the right medication and dosage for individual patients. This approach reduces the risk of adverse effects and improves overall treatment outcomes. For example, pharmacogenomic testing can identify variations in the CYP2D6 gene, which affects the metabolism of the antipsychotic drug aripiprazole. Patients with certain CYP2D6 variants may metabolize the drug too quickly or too slowly, leading to either insufficient efficacy or increased side effects. By identifying these genetic variants, clinicians can adjust the dosage of aripiprazole or choose alternative medications, ensuring more effective and safer treatment for conditions such as schizophrenia or bipolar disorder.

Gene therapy

Advancements in gene therapy are opening new treatment avenues for neurological disorders. By correcting or replacing defective genes, gene therapy has the potential to treat or even cure conditions that were previously deemed untreatable. Techniques such as CRISPR-Cas9 and viral vector delivery are being developed to target specific genetic mutations associated with neurological diseases. One notable example is the treatment of spinal muscular atrophy (SMA), a severe neurodegenerative disorder caused by mutations in the SMN1 gene. Gene therapy, in this case the use of the viral vector-delivered drug onasemnogene abeparvovec (Zolgensma), delivers a functional copy of the SMN1 gene to the patient's cells. This treatment has shown significant improvements in motor function and survival rates in infants with SMA. These therapies offer hope for patients with rare and severe neurological conditions, providing a path to long-term recovery and improved quality of life.

The integration of biomarkers, genomic sequencing, epigenetics, pharmacogenomics, and gene therapy into neurology represents a paradigm shift in how neurological disorders are understood and treated. These advancements not only enhance our ability to diagnose and treat these conditions but also pave the way for more personalized and effective healthcare solutions. To learn more, download our whitepaper: