Genetic testing can be widely applied to people with different age groups and underlying conditions, hinging upon the purpose of getting the test. Genetic tests are often recommended in these following groups:
- Health-conscious people who seek for proactive healthcare plan to promote overall health and to minimize the risk of developing certain diseases in the future.
- People who pose risk factors of cardiovascular or neurological diseases, e.g. diabetes, hypertension, dyslipidemia, being physical inactive, obesity and smoking.
- People with family history of hereditary diseases, e.g. cardiovascular diseases, neurological diseases and cancers.
- Couples who are planning to have babies. Sperm or egg donors.
- People who need to know about risks related to genetic abnormalities that can be passed to their children.
- Pregnant women or women who are undergoing IVF and preimplantation genetic testing is indicated before embryo transfer.
- Patients who have taken or who are planning to take certain medications. Patients with underlying diseases who have taken several medications. People who want to know their drug response to ensure drug efficacy and safety in the future.
- Patients with certain health issues, e.g. cardiovascular diseases, infections, rheumatoid arthritis, autoimmune diseases or cancers.
How to get genetic testing?
After receiving pre-counseling by a genetic trained healthcare provider, genetic test generally involves 3 steps:
- Sample collection: Sample, e.g. saliva, blood, buccal swab or tumor biopsy will be collected at the hospital. The type of sample depends on the type of genetic test. Refraining from food and drink is not required.
- Genetic analysis: Collected sample will be sent to genetic laboratory for analysis and interpretation which normally takes 2-6 weeks, depending on the selected test.
- Receiving the result: Results will be informed by the doctor. After genetic counseling, additional recommendations or investigations might be required to make an appropriate plan.
Get to know “NEXT – GENERATION SEQUENCING (NGS)”
As a highly promising concept, Precision Medicine deploys genomic advancements and human genomic resources to develop precise healthcare initiatives, covering all medical purposes.
Next – Generation Sequencing or NGS refers to large-scale DNA sequencing technology which is able to determine the order of nucleotides or DNA base sequence in entire genomes or targeted regions of DNA or RNA. Considered advanced technology, NGS can sequence a large number of genes at once to assess disease risks or identify disease-associated variants to help matching patients to the right therapies. Due to rapid evolution of NGS, it offers ultra-high throughput, scalability and speed with high sensitivity to detect genetic alterations. Analyzed by computer-based system using international human genomic resources, the results are accurate, aiding in diagnosis and treatment planning.
NON – INVASIVE PRENATAL TESTING (NIPT)
“Screen for genetic disorders to best guide your fetus’s health.”
Non-Invasive Prenatal Testing or NIPT is a non-invasive screening test used to determine the chromosomal abnormalities of the fetus using maternal blood. As a highly reliable prenatal screening tool, NIPT can detect fetal risks of developing a wide range of genetic diseases caused by chromosomal anomalies, e.g. Down’s syndrome, Edwards’ syndrome and Patau’s syndrome. In addition, NIPT can identify sexual chromosomes as well as certain chromosomes causing congenital disorder or disability and fetal death. NIPT also helps to minimize the need for unnecessary amniocentesis, an invasive testing to diagnose chromosomal conditions by removing amniotic fluid from the uterus. The result obtained from NIPT leads to a proper pregnancy care and planning. NIPT is recommended when the gestational age is 10 – 20 weeks. Using Whole-Genome Next Generation Sequencing (NGS), the test is highly precise and accurate. More importantly, it holds no associated risks for the mother and the fetus.
PREIMPLANTATION GENETIC TESTING FOR ANEUPLOIDY (PGT-A)
“Fulfill the dream. Rise up the chance of pregnancy.”
Preimplantation Genetic Testing for Aneuploidy or PGT-A is used to identify chromosomal abnormalities in embryos created through IVF prior to transfer to the uterus. Transferring the healthiest embryos can substantially optimize the chance of pregnancy, contributing to minimized risks of miscarriages and genetic defects with quicker time to pregnancy and reduced monetary burden. PGT-A is highly recommended in women aged over 35, couples who have had unsuccessful IVF cycles, women with more than 2 miscarriages before 12 weeks of gestation and women or men who have family history of genetic disorders
POLYGENIC RISK SCORE IN CARDIOVASCULAR DISEASES
“Understand your risk. Ensure your heart’s heart.”
Coronary artery disease and atrial fibrillation – an irregular heart rhythm (arrhythmia) are common heart diseases found in adults and the elderly. Risk factors often include advancing age, hypertension, diabetes, dyslipidemia, smoking and having a family of cardiovascular, neurovascular diseases or atrial fibrillation. Mounting clinical evidence has suggested that inherited DNA sequence variants play a significant role in conferring risk for heart diseases. Polygenic Risk Score is a genetic test intended to estimate the relative risks of developing certain heart diseases. While taking individual’s risk factors into account, the result is calculated according to an individual’s genotype profile compared to the general population. Those with higher scores are more likely to develop heart diseases. Therefore, to lower the risks, lifestyle modification is strictly indicated along with regular screening and regular follow-up, allowing effective and prompt treatment whenever needed. This test is recommended for people aged over 40, people with risk factors, e.g. hypertension, diabetes or dyslipidemia and people with family history of heart disease.
COMPREHENSIVE GENOMIC PROFILING (CGP)
“Powerful genetic insights to guide efficient, personalized treatment decisions for cancers”
Despite the fact that cancers are caused by different factors among individuals, genetic mutations can significantly contribute to cancer development. Comprehensive Genomic Profiling (CGP) uses the Next-Generation Sequencing (NGS) technology to identify a number of variants across hundreds of genes known to drive numerous types of cancer. After consulting with the clinical oncologist once the diagnosis of cancer is made, biopsy sample will be collected and sent to genetic laboratory for analysis. The results can be received within 4-6 weeks and the medical counseling will be made by the clinical oncologist.
The result of CPG provides powerful insights to guide efficient, personalized cancer treatment decisions made by the oncologists in order to obtain the best possible outcomes based upon individual’s genetic profile. Compared to conventional tests, e.g. single-gene test and cancer hotspot panel, all genomic alterations, both prevalent and rare biomarkers can be simultaneously analyzed. It significantly saves time and biopsy samples while reducing the risks and costs related to multiple biopsies. Moreover, by assessing a broad panel of genes, it may increase the chance of finding actionable alterations to plan for additional therapeutic actions.
POLYMERASE CHAIN REACTION (PCR)
“The role of multiplex PCR test in diagnosing and managing infectious diseases”
A molecular laboratory test – multiplex PCR is used for simultaneous amplification that utilizes different primers in a single tube. Since it can detect genetic materials of a wide variety of pathogenic microorganisms, e.g. bacteria, fungi, parasites and viruses, it has been applied in diagnosis of several infectious diseases. As a widespread molecular biology technique, multiplex PCR can rapidly identify causative agents with high degree of accuracy, compensating for the loss of blood culture sensitivity. To obtain the result of multiplex PCR, it takes only 3-4 hours rather than 3-4 days consumed by blood culture. Besides detecting the types of pathogen, multiplex PCR offers an accurate identification of antibiotic resistance profiles that could be used in therapeutic purposes, enabling the doctor to select appropriate antibiotic drugs based on antibiotic susceptibility profiles and limit the unnecessary use of ineffective antibiotic medications. As a result, effective treatments can fully resolve infections, leading to a quick recovery while minimizing antibiotic resistance in the community accelerated by the misuse of antibiotics.
Genetic test and rheumatic diseases
“Enhance diagnosis accuracy. Promote treatment safety.”
Rheumatic diseases refer to a group of autoimmune and inflammatory disorders affecting joints, cartilages, tendons, ligaments, muscles and bones. Evidence favoring genetic predisposition to different rheumatic diseases has been revealed, such as the HLA-B27 test aiding in confirmatory diagnosis of ankylosing spondylitis and the HLA-B5801 test evaluating the risk of severe adverse reactions to allopurinol – uric acid lowering agent used in gout. In addition, other genetic tests are aimed at detecting or ruling out the presence of hereditary predisposition to rare conditions causing inflammations and affecting a wide range of body parts.
Genetic testing plays significant roles in rheumatic diseases, both assisting diagnosis and promoting treatment safety. Ankylosing spondylitis, a form of arthritis that causes chronic back pain, is often found in children, adolescents and adults. With or without joint inflammation, symptoms of ankylosing spondylitis might include back pain and stiffness in the back, especially in the morning or after periods of inactivity. To diagnose ankylosing spondylitis, it usually involves the examination of signs and symptoms, blood tests to check for markers of inflammation and MRI scan. Interestingly, people who have a HLA-B27 gene are at a greatly increased risk of developing ankylosing spondylitis. Therefore, genetic test for the HLA-B27 gene helps aiding diagnosis of ankylosing spondylitis while taking into account other relevant tests. Regarding treatment aspect, the role of genetic testing to enhance safety has been addressed in patients diagnosed with gout brought on by the accumulation of uric acid in the joints, causing the inflammation and intense pain. The treatment goal is to lower the amount of uric acid in your blood while reducing the inflammation and pain associated with gout attacks. If left uncontrolled, too high level of uric acid in the blood repeatedly induces inflammation of the joints, urging the patients to take excess amount of pain killers and putting the patients at greater risk of experiencing undesired effects, such as kidney failure. Several medications used to lower the level of uric acid are available. Among these medications, allopurinol is widely prescribed. Although it is generally well tolerated, allopurinol is associated with life-threatening hypersensitivity reactions. The HLA-B27 gene has been firmly proven as a genetic marker for allopurinol-induced severe hypersensitivity. If the HLA-B27 allele is present, allopurinol is no longer first-line treatment and other medications must be prescribed instead.
Genetic test and neurological diseases
“Guiding decisions towards prevention and more effective treatments”
Knowledge of the association between genetic variations and brain diseases has substantially increased over the past decades. Over 80% of genes in our body are associated with a wide range of neurological diseases. More importantly, approximately 40% of known genetic conditions affect the neurological system. These genetic alterations can substantially predispose each individual to neurological diseases, for instance, the mutation of APOE4 gene increases the risk of Alzheimer’s and is associated with getting the disease at an earlier age. In addition, recent molecular genetic studies have revealed that a number of genes are related to Parkinson’s disease, epilepsy and stroke. Genetic testing helps to screen for the risks of developing certain neurological diseases, particularly in those who have yet to exhibit any abnormal sign, allowing a preventive healthcare plan and neurological care best suited for each person. Moreover, genetic testing significantly enhances diagnostic accuracy while shortening time consumed for ruling out in patients present with neurological manifestations. This leads to an effective treatment given in a timely manner. Due to advanced genetic technology, the Next-Generation Sequencing is able to assess genetic abnormalities in hundreds of genes, including certain variants which contribute to rare neurological diseases and autoimmune neurological disorders in a single sequencing experiment.
DRUG – GENE PROFILE
“Promoting drug safety and treatment precision based upon unique genetic makeup”
Currently, drug selection and dosage determination are based upon general population data, both drug efficacy and safety. Although a number of medications might be “one size fits all”, some other medications do not work exactly the same way for everyone. This is because genes diversely affect a person’s response to drugs. Drug-Gene Profile Test is a pharmacogenomic test to identify the role of an individual’s genome in drug response. It analyzes how the genetic makeup of people influences their response to a variety of drugs, allowing effective and safe medications to be prescribed while minimizing the risks of drug hypersensitivity reactions hinging upon unique genetic profile. The test covers a broad range of medications, e.g. anticoagulants, lipid-lowering agents, painkillers, sleeping pills and psychiatric drugs, anticonvulsant drugs, immunosuppressants and certain medications used in cancers, heart diseases, infectious diseases, peptic ulcers and allergy.
