“Humans carry approximately 20,000 genes in every cell of the body. Each gene provides instructions to produce proteins, many of which work together to support complex biological systems. We inherit half of our genes from each parent, and we have a pair of each gene. While most function normally, all individuals carry some genetic changes, or variants, which may or may not lead to health conditions,” says Juliana.

Genetic testing allows us to detect these changes and understand their potential clinical impact. It is generally classified into two categories:

• Genetic screening, which is typically offered to healthy individuals without symptoms to assess risk.
• Diagnostic testing, which is used for individuals exhibiting symptoms or those at risk due to family history.

Various types of genetic screening are available, depending on the genes tested:

Here are some of the most common forms of screening:

1. Newborn screening: Conducted shortly after birth to detect rare genetic and metabolic conditions that can cause serious health issues if untreated. Many of these conditions are inherited in an autosomal recessive manner, where both parents are carriers of one affected gene and one normal gene.
2. Reproductive carrier screening: Recommended for couples planning to have children. This screening identifies if both partners are carriers of the same autosomal recessive genetic disorder. If so, there's a 25% chance their child will be affected. Options include in vitro fertilisation (IVF) with pre-implantation genetic testing (PGT) to select unaffected embryos, or prenatal diagnostic testing as early as 11 weeks’ gestation during natural conception.
3. Prenatal cell-free DNA screening: This screening analyses fragments of the baby’s DNA in the mother’s blood to detect chromosomal abnormalities, such as extra or missing genetic material. If a pregnancy is found to be at high risk, diagnostic testing is recommended for confirmation.
4. Hereditary disease screening: Assesses risk for adult-onset conditions such as hereditary cancers, cardiac diseases, neurodegenerative disorders, and metabolic conditions like familial hypercholesterolaemia.
5. Multi-cancer early detection (MCED): This emerging form of screening detects early signs of cancer by identifying circulating tumour DNA in the blood. Early detection improves the chances of timely treatment and better outcomes.
6. Pharmacogenetic testing: Determines how an individual's genetic makeup affects their response to certain medications, aiding in selecting the most effective treatment options.

Juliana explains that genetic screening helps identify genetic changes that may lead to health conditions in an individual or their future children. The immediate benefits depend on the specific genes tested. For instance, screening for adult-onset conditions such as cancer, cardiac diseases, neurodegenerative disorders, or metabolic conditions can reveal an individual’s predisposition to developing these diseases later in life.

With this knowledge, individuals can take proactive steps. These may include early medical screening, preventive treatment, or lifestyle adjustments such as improving diet and increasing physical activity. This forward-looking approach not only helps manage potential symptoms but also supports long-term health and may contribute to a longer, healthier lifespan.

Genetic screening plays an increasingly important role in improving treatment outcomes by identifying genetic changes that may place an individual at higher risk for certain health conditions. This information allows healthcare providers to tailor medical decisions to a person’s unique genetic profile.

Juliana, explains that some medications are designed to work more effectively for people with specific genetic variants. For example, the drug Olaparib has been shown to benefit cancer patients with mutations in the BRCA1 or BRCA2 genes. Knowing whether a patient carries one of these changes enables more precise treatment planning.

In addition, pharmacogenetic screening, a test that analyses how genes influence a person’s response to certain medications, can help determine which drugs are likely to be most effective or better tolerated. This approach not only reduces the risk of side effects but also increases the likelihood of successful treatment.

With rising concerns about data privacy, individuals undergoing genetic testing should take steps to ensure their information is handled responsibly and ethically. Juliana recommends choosing laboratories that are accredited by recognised bodies such as CAP (College of American Pathologists) or CLIA (Clinical Laboratory Improvement Amendments), as these facilities follow strict protocols for data protection.

Before proceeding with any genetic test, it is important to read the consent form carefully. This document outlines how your genetic data will be managed, including whether it will be anonymised, stored, or shared. Even if your data is anonymised, you retain the right to decline storage or sharing after testing.

The same considerations apply when genetic testing is offered as part of a medical research study. Ensuring your participation is fully informed, voluntary, and aligned with your preferences helps safeguard your data and your rights.

To make genetic screening more accessible and affordable, one of the most effective strategies is to integrate it into the public healthcare system with full or partial funding. However, given the high costs and specialised expertise required, it may not be feasible for governments to subsidise all types of genetic screening.

Currently, only a limited number of genetic screening services, such as newborn screening and Thalassaemia screening, are available in public healthcare across the region. In some countries, research projects have been introduced to explore the feasibility of reproductive carrier screening for couples planning to have children, as well as targeted cancer screening initiatives. However, broader gene panels and more advanced technologies are still largely confined to the private sector.

To bridge this gap, public-private healthcare collaborations could be explored as a way to reduce costs and promote the wider use of genetic screening within the community. At the same time, greater public awareness is needed to highlight the role of genetic screening in improving healthcare management, supporting disease prevention, and enhancing life expectancy.

Genetic counselling should also be an essential part of the process, provided both before and after testing. This ensures individuals are fully informed about the benefits and limitations of screening, and understand the implications of their results for their personal and family health.