Need for Molecular Diagnostics

Medically reviewed by Dr. Vivek Vishnu

Molecular diagnostics is a vital branch in the field of genomics which is associated with the analysis of nucleic acids (DNA and RNA) to detect multiple infectious diseases, screening of genetic abnormalities, and monitoring of disease progression.

DNA and RNA are biomolecules that play a major role in the genetic code and protein synthesis critical for life. Molecular diagnostics majorly focuses on studying and identifying any changes in the sequences (DNA or RNA) which are associated with any diseases or abnormalities. It enables precise and early detection of clinical conditions improving treatment and prevention strategies.

What’s the need for Molecular Diagnostics?

Over the past few years, after the COVID-19 pandemic, the field of molecular diagnostics has experienced remarkable progress and expansion around the globe. Molecular diagnostics has emerged as a vital player in India due to the rapid urbanization and population growth, diet & lifestyle, the prevalence of infectious diseases, and understanding the molecular mechanism of an individual patient's disease termed as personalized medicine.

*Rapid urbanization and population growth:

The increase in the Indian population and urbanization has a major effect on morbidity, mortality, and health trends. Increasing population leads to higher risk of disease transmission and identification of new pathogens like SARS-COV2 which resulted due to overcrowding of humans and their livestock in China. Molecular diagnostic provides the platform for identifying and tracking such new threats and addressing any disease outbreak.

*Diet and Lifestyle

A healthy lifestyle and good nutrition are very important for good health. The health and disease of individuals and populations are the result of genetics and environment. Molecular diagnostics make it possible to study the molecular sequences associated with many human diseases and to predict and treat several conditions accordingly.

*Prevalence of infectious diseases:

Infectious diseases such as Tuberculosis, HIV, Dengue, and Hepatitis are still predominant in India. Recent infections such as Swine flu and Coronavirus are emerging at a higher rate and spreading more rapidly than ever in the communities. Molecular diagnostics enables precise, rapid, and accurate identification of such diseases which indeed helps in timely treatment.

*Need for Personalized medicine

It’s a personalized approach to disease prevention and treatment considering the differences in individual genes, environment, and lifestyle. The genetic variation among the population can affect the treatment course and drug of action. The main goal of molecular diagnostics is to identify and target the right treatment to the right patients at the right time.

Types of Molecular Diagnostics tests:

Polymerase chain reaction (PCR):

In Molecular Biology, PCR is the most revolutionary technique. PCR is used for the identification and amplification of unique sequences of target DNA. It allows for precise and rapid identification of the target DNA’s presence or absence. The applications of PCR are multiple in clinical scenarios, such as identifying genetic mutations, infectious diseases, and Cancer biomarkers. Multiplex PCR such as Film array Bio-fire can enable us to target multiple organisms within one and less time.

DNA sequencing:

In General, sequencing is to determine the exact sequences of a DNA molecule. Sequencing technologies have evolved to Next-generation sequencing (NGS DNA testing), which is more sensitive, cost-effective, and can sequence the entire genome very quickly. NGS is mostly used in the diagnosis of cancer mutations, post-natal genetic diseases, and precision medicine to aid in providing the right treatment to individuals.

CRISP-R:

CRISPR (clustered regularly interspaced short palindromic repeats) is the latest genome editing technology for sensing nucleic-acid-based biomarkers for the identification of disease-related genes or any mutation in genetic diseases. This diagnostic technology is fast, affordable, and aids in the ultrasensitive sensing of biomarkers at the POC.

Microarray Technology:

Microarray is a widely used tool for studying biomolecules targeting a wide range of markers simultaneously in the genome. This technology is mostly used for studying gene expression profiling and identifying genetic mutations in multiple diseases. However, in clinical microbiology and cancer diagnostics array technology is a valuable diagnostic tool to aid in therapy.

Applications of Molecular Diagnostics:

Over time traditional diagnostics technology has been overpowered by Molecular diagnostics which is a rapidly developing area of laboratory medicine. India is a genetically diverse country, molecular diagnostic plays a vital role in addressing the challenges of cancer, infectious diseases, and congenital abnormalities.

Infectious diseases:

*Detection and Quantification by real-time PCR for infectious diseases is well established in Molecular biology. Molecular diagnostics can identify between various hepatitis virus strains (A, B, C, D, and E), HIV-1/2 viral loads, and diagnosis of latent virus reactivations such as polyomavirus BK or CMV (cytomegalovirus) in transplant patients.

*Rapid detection of TB is very crucial in the spread of the disease. Molecular tests like GeneXpert, Lamp-based PCR, and TB-PCR tests enable the clinician to detect TB and drug resistance within hours compared to the microbial culture which takes several days.

Cancer:

*Globally cancer is a complex disease affecting millions of lives. Molecular diagnostics allow for early detection, specific diagnosis, and rapid treatment of cancers using cancer-specific biomarkers. Few tests are used to determine the risk of future disease in an individual who may be healthy at the time of testing.

*Molecular methods such as DNA microarray can be used for the comprehensive detection of many cancer-associated mutations or gene profiling in the diagnosis and therapeutic evaluation of cancer disease.

Congenital diseases:

*The increased demand for genetic and genomic information has led to the rapid expansion of molecular techniques. Chromosomal microarray analysis (CMA), Fluorescent in situ hybridization (FISH), and cytogenetic analysis (karyotyping) can be used to detect gross mutations like whole and large-scale duplications, gene deletions, or rearrangements.

*Prenatal genetic testing identifies genetic abnormalities and enables parents to make pregnancy-related decisions and management of the condition. Prenatal diagnostic testing often provides a definitive result, confirming that the fetus either does or does not have a specific disorder.

Conclusion:

Molecular diagnostic techniques and platforms have great potential in India and around the globe in infectious diseases management, Genetic abnormalities, and cancer treatment. The combination of molecular technologies based on the user's need can provide accurate and timely diagnosis of diseases and facilitate precision treatment. In India, Understanding the challenges in molecular technologies and using them can uplift the lives of citizens and healthcare sector.