A decade ago, genomic testing was largely confined to research laboratories and highly specialised medical centres. Today, a person's genome can be sequenced within weeks, and at a fraction of the original cost, bringing one of medicine's most powerful technologies within reach of routine clinical care.
From predicting an individual's risk of heart disease to diagnosing rare genetic conditions and tailoring cancer treatments, genomics is beginning to reshape how healthcare is delivered. Singapore has invested heavily in precision medicine infrastructure, positioning itself at the forefront of this transformation.
Dr. Saumya Jamuar, a clinical geneticist, explains how genomics is already being used in practice, where it is delivering the greatest impact, and what still needs to happen before it becomes a standard part of patient care.
The impact of genomics is clearest in conditions that used to take years to identify.
Children with unexplained or complex conditions were historically caught in what Dr. Saumya calls a diagnostic odyssey. They would be seen by multiple specialists, given two or three misdiagnoses, before waiting another five to seven years on average to receive the right answer. With whole genome sequencing, these patients can get the correct diagnosis within a week.
“Multiple loops, multiple dead ends, multiple wrong directions,” Dr. Saumya says. “Now with whole genome sequencing, we can actually streamline the entire process. We can get the answer to them within a week if we need to.”
He describes an 18-month-old girl admitted with severe epilepsy. Genetic testing identified a change in a glucose transporter gene, meaning glucose was not reaching the brain properly. The treatment — a ketogenic diet providing ketones as an alternative fuel — produced a dramatic reduction in seizures. Without the use of genomic testing, Dr. Saumya shared that the standard treatment journey would have been to try multiple anti-epileptic medications over months before arriving at the same answer.
In pregnancy, non-invasive prenatal testing (NIPT) has effectively replaced maternal serum screening as the first-line screening tool for chromosomal conditions, including Down syndrome, and reduced the number of invasive procedures such as amniocentesis that need to be performed on expectant mothers.
According to Dr. Saumya, the test is performed using the mother's blood with 99.6% accuracy, carrying no risk to the pregnancy. Newer versions now screen for neurodevelopmental disorders arising from new mutations in the baby's DNA — conditions with no family history and previously undetectable without invasive testing.
In oncology, genomics has been standard practice for several years. Tumors are now classified not just by their location but by their molecular basis — which gene is affected — allowing oncologists to select treatments targeted specifically for that variant. This has improved outcomes across a range of cancers.
As genomic technologies become more accessible and affordable, attention is increasingly turning to how they can be applied more widely across healthcare.
Dr. Saumya Jamuar frames clinical genomics across three areas: prevention, diagnosis, and treatment, with each at a different stage of readiness, but all are already in active use.
Prevention through genomics, according to Dr. Saumya, is where Singapore is most visibly heading towards, particularly through initiatives such as HealthierSG and PRECISE (Precision Health Research, Singapore).
For example, a standard health screening can tell you if your cholesterol is borderline, while an additional layer of genomic testing tells you whether your underlying genetic profile puts you at a significantly elevated risk of coronary artery disease — even before traditional markers flag it.
"Previously, if a 42-year-old male comes in with just a borderline LDL level," Dr. Saumya shares. "The way we would advise him to manage it would be through lifestyle changes, a healthier diet, and then he would come back, and the cycle repeats. But when you add a genomic score, you may realise this individual is at a very high risk of developing coronary artery disease. That's when you can order a calcium score test and be more aggressive about managing their cardiac risk factors."
These risk scores, called polygenic risk scores, were, until recently, unreliable for non-Caucasian populations. A 2019 study showed they performed well in Europeans but were little better than chance in other ethnic groups. That has changed in recent years, largely because Singapore's National Precision Medicine Programme completed sequencing of 100,000 healthy Singaporeans, creating a reference database for what a healthy local genome looks like.
This progress reflects years of investment Singapore has put in precision medicine infrastructure and genomic research at the national level.
The Ministry of Health’s (MOH) investment in precision medicine has positioned Singapore ahead of most comparable health systems. The National Precision Medicine Programme is now in its third phase, with 100,000 healthy Singaporeans sequenced and a clear framework in place.
In February this year, MOH announced it would subsidise genetic testing for breast and ovarian cancer, along with the associated surveillance and management pathways for those found to carry relevant gene mutations. Medisave use for genetic testing has also been expanded.
Dr. Saumya expects coverage to widen as evidence accumulates and the economics of testing and management continue to improve.
For clinicians who do not routinely work in genomics, Dr. Saumya offers a practical shorthand: the rule of "too”.
Specific red flags that, according to Dr. Saumya, warrant a genetics referral include:
Dr. Saumya is up front about what genomics cannot yet do consistently.
Of the 20,000 genes in the human genome, only around 7,700 are currently understood. Three new gene-disease associations are being identified every week, but the remaining 13,000 genes are still largely uncharacterised.
A related problem is variants of uncertain significance (VUS) — genetic changes found during sequencing that cannot yet be classified as harmful or benign. Telling a patient they carry a variant of unknown meaning creates anxiety without a clear path forward. This is a known limitation of the field, and managing it requires careful pre-test counselling.
There is also the question of incidental findings. In approximately 3% of healthy individuals, whole genome sequencing will identify something clinically significant unrelated to why the test was ordered — a finding as unexpected as a scan for one condition revealing another. Patients should be asked before testing whether they want to receive such findings.
Despite these limitations, genomics is already influencing everyday medical decisions in ways that many patients may not realize. One application of genomics that affects day-to-day clinical practice is pharmacogenomics — understanding how a patient's genetic makeup affects their response to medication.
An example of this is the drug clopidogrel (Plavix), a blood thinner used to prevent blood clots. Around 50% of Singaporeans carry a variant in the gene CYP2C19 that affects how the drug is metabolised, meaning that a standard dose may not work as intended in half the patients receiving it. Public healthcare clusters are now rolling out routine testing for this variant and adjusting doses accordingly. This is precision medicine applied not to a rare disease, but to a drug prescribed daily across general and cardiology practices.
Dr. Saumya predicts that genomics will move from specialist practice to mainstream care within the next four to five years. The science exists; the government infrastructure is being built. However, the gap, as he sees it, is clinical adoption.
“The science and tools are here. There's no running away from it,” Dr. Saumya notes.
MOH is also looking at financing infrastructure, so it's coming there, but not fully. What we are lacking right now is clinical adoption.”
For patients who have already had direct-to-consumer tests through companies like 23andMe or CircleDNA, he notes a practical consideration: Ministry of Health guidelines do not permit direct-to-consumer genetic data to be used in clinical care. The most useful step for those patients is to convert that curiosity into a formal clinical test — whole exome or whole genome sequencing — that generates results usable in actual patient management.
The $100 genome test is coming soon. The next challenge will be turning that information into something that meaningfully improves patient care.
