Genetics

Key Concepts in Medical Genetics

Genetics is the science that studies heredity and variability in living organisms. In the medical context, it focuses on mutations that affect human health. The key concepts include:

• Gene — a segment of DNA that encodes biological information.

• Mutation — any change in the genetic sequence.

• Hereditary disease — a disease caused by DNA defects.

• Genotype and phenotype — internal and external characteristics of an organism.

The development of genetics has led to the identification of more than 6,000 hereditary diseases, including Down syndrome, cystic fibrosis, hemophilia, and oncogenic mutations.

Methods

Modern methods make it possible to study the genetic nature of diseases and select personalized treatments.

Methods for Studying Human Genetics

These include:

• Karyotyping — analysis of chromosome structure and quantity.

• Fluorescent In Situ Hybridization (FISH) — detection of chromosomal rearrangements.

• Molecular genetic tests — detection of point mutations.

• Next-Generation Sequencing (NGS) — high-precision diagnostics, including:

  • WGS (Whole Genome Sequencing) — complete sequencing of the human genome. It helps detect rare and complex genetic changes.

  • WES (Whole Exome Sequencing) — analysis of all exons, the protein-coding regions of DNA. This is a more cost-effective and efficient way to identify pathogenic variants.

NGS is revolutionizing the diagnosis of hereditary and oncological diseases. It allows the detection of gene variants associated with predispositions to cancer, diabetes, autism, and other illnesses.

mRNA analysis is also used to determine the activity of specific genes, especially in oncology. This helps assess tumor progression and select the most effective treatment.

Methods for Treating Hereditary Diseases

• Gene therapy — introduction of a normal gene copy.

• Targeted therapy — drugs aimed at specific molecular targets.

• Personalized therapy — selection of treatment plans based on the patient’s genetic profile.

The Role of Genetics in Medicine

Genetics has changed the approach to diagnosing and treating diseases. Thanks to this science, it is now possible to:

• Detect disease predispositions before symptoms appear.

• Personalize treatment based on the patient’s genetic profile.

• Increase diagnostic accuracy.

• Perform reproductive screening to plan pregnancies.

In oncology, biomarkers are widely used, such as:

• TMB (Tumor Mutational Burden) — the number of mutations in a tumor, which predicts the response to immunotherapy.

• MSI-H/dMMR — microsatellite instability and DNA mismatch repair deficiency, which are important for selecting therapies in colorectal and other cancers.

This approach enables personalized medicine, improving treatment effectiveness and reducing side effects.

Medical-Genetic Consultations

Consultations with a medical geneticist are necessary:

• When planning a pregnancy.

• In families with hereditary diseases.

• When oncogenic mutations are detected.

• In cases of congenital anomalies in newborns.

During a consultation, a medical history is collected, a family tree is drawn, genetic tests are prescribed, and a prevention or treatment plan is developed.

Genetics is the science of the future of medicine. Thanks to new diagnostic methods such as NGS and mRNA analysis, doctors can now influence the outcomes of many diseases. If you would like to undergo genetic testing, the Marus platform can help you find a clinic and genetic specialist in Russia, tailored to your individual needs.