What is whole genome sequencing?
Whole genome sequencing (WGS) reads your DNA from one end to the other. Human DNA is about 3 billion chemical letters, called bases. More than 99% of them are the same in everyone. WGS looks for the differences, called variants, that can affect health.
It reads the DNA you were born with, so it estimates future risk. It does not measure what is happening in your body today. The genetic testing page explains how inherited-risk testing works in general.
How is it different from an exome or a gene panel?
All three read DNA. They differ in how much of it they read:
| Test | What it reads | Trade-off |
|---|---|---|
| Gene panel | A chosen set of genes, such as those linked to inherited cancer | Answers one question; sees nothing outside the chosen genes |
| Exome sequencing | The protein-coding parts of all genes, about 1% of the genome | Covers the regions where most known disease-causing changes sit; misses changes outside them |
| Whole genome sequencing | The whole genome, including the long stretches between genes | Can find a variant in any part of the genome; most of what it reads cannot yet be interpreted |
Even WGS has blind spots. The Medical Genome Initiative, a consortium of US and Canadian healthcare and research organizations, lists change types that a laboratory must validate separately before it can report them:
- Repeat expansions, such as those behind fragile X syndrome and Huntington disease.
- Genes with a near-identical copy, such as SMN1 (spinal muscular atrophy), HBA1 and HBA2 (alpha thalassemia), PMS2 (a Lynch syndrome gene) and CYP2D6 (a drug-processing gene).
- Mosaic variants, present in only some of the body's cells.
- Balanced rearrangements, where a piece of DNA is swapped or flipped rather than lost.
The group says any such gap should be stated on the test report. Ask which of these the laboratory reports.
How do the two iHope Clinic packages differ?
New Dawn Health offers WGS as two packages at iHope Clinic in Xinyi District, Taipei. This comparison comes from each package's own description in our booking record:
| Described | Whole Genome Sequencing (WGS) Genetic Testing | Comprehensive Whole Genome Sequencing (WGS) Package |
|---|---|---|
| Scope | "Targeted" WGS, focused on common adult conditions; designed with the clinic's medical director, a nephrologist | Full-spectrum sequencing of the whole genome |
| Conditions reported | Stroke, blood lipids and alcohol metabolism; colorectal, stomach, liver, pancreatic, lung, breast and prostate cancer predisposition; Alzheimer's and Parkinson's disease; kidney health | Adds rare single-gene disorders, carrier status for family planning, and polygenic risk profiles |
| Drug-gene results | Not mentioned | Pharmacogenomics across many medicine groups, including heart, cancer, pain and psychiatric drugs |
| Re-analysis | Not mentioned | Data stored so it can be re-interpreted as knowledge grows |
What the descriptions leave open
Ask about these before you book; the descriptions do not settle them:
- Whether the first package reads the whole genome and reports a subset, or reads only selected regions. Its description says both "whole genome" and "focused on high-impact disease loci".
- Which laboratory sequences and interprets the sample, at what depth, and with what accreditation.
- Whether either report includes the ACMG secondary-findings genes, and whether you can opt in or out.
- Whether carrier results cover SMN1 and the alpha-thalassemia genes, which need special analysis.
- Whether the common-disease sections rest on single genes, on APOE, or on polygenic risk scores.
- Whether variants of uncertain significance are reported.
- Whether you receive your raw data files, and what re-analysis includes and costs.
Your coordinator confirms the clinic's answers when you book.
What can a healthy person learn?
Four kinds of result matter for someone without symptoms. The evidence behind them differs widely:
| Result | What it means | Evidence and limits |
|---|---|---|
| Actionable inherited risk | A harmful variant in one of the 84 genes on the ACMG SF v3.3 list (2025). Examples: BRCA1 and BRCA2, the Lynch syndrome genes, LDLR, APOB and PCSK9 (familial hypercholesterolemia), and heart-rhythm genes. | The strongest category: genes chosen because care can change. Uncommon: in a 2024 Taiwan Biobank analysis, 25 of 1,496 Taiwanese genomes (1.67%) carried one from the version 3 list. |
| Carrier status | One copy of a recessive variant. Harmless to you; it matters if your partner carries a variant in the same gene. | ACMG (2021) recommends offering carrier screening to everyone pregnant or planning a pregnancy. The same Taiwanese study's carrier analysis put 1 in 25 couples at risk. |
| Gene-drug results (pharmacogenomics) | Variants that change how your body handles certain medicines. | Established for specific pairs that the US FDA lists, such as HLA-B*15:02 with carbamazepine and CYP2C19 with clopidogrel. |
| Common-disease risk scores | Many small-effect variants added into a polygenic risk score, for conditions such as heart disease. | The weakest. NHGRI says these scores give relative risk only, are not yet routinely used, and may be valid only for European ancestry. |
If both partners carry a variant in the same recessive gene, each pregnancy has a 25% chance of an affected child. That is why carrier status matters before a pregnancy, not after.
Gene-drug results: the Taiwanese example
- Taiwan, 2011: 4,877 people at 23 hospitals were tested for HLA-B*1502 before taking carbamazepine, an epilepsy and mood drug.
- The result: the 7.7% who carried it were advised not to take the drug. No one who tested negative developed Stevens-Johnson syndrome, a severe skin reaction, against about 10 cases expected from past rates.
- Europe, 2023: the PREPARE trial tested a 12-gene drug panel before prescribing. Among patients with an actionable result, 21.0% had clinically relevant side effects with the panel, against 27.7% without it.
Both studies used targeted tests, not whole genomes. The FDA adds that listing a gene-drug pair does not necessarily mean it advises testing before prescribing that drug.
What happened when healthy adults were sequenced
MedSeq, a US pilot trial, randomized 100 generally healthy adults aged 40 to 65. Half received a genome report on top of a family-history review:
- 11 of the 50 genome patients (22%) learned of a new single-gene disease risk.
- Only 2 of the 50 (4%) showed signs of the condition that result predicted.
- Doctors recommended new clinical actions for 34% of the genome group, against 16% of the family-history group.
The authors concluded that genome findings in healthy adults were of uncertain clinical value, and could prompt extra care of unclear value.
What can't it tell you?
- Inherited variants across the genome, with the blind spots listed above
- A small number of actionable risks, carrier results and gene-drug results
- A data set that can be re-read as knowledge grows, if the data is kept
- Find a cancer that is already there. It reads inherited DNA, and the US National Cancer Institute says only about 5–10% of cancers are inherited. Colonoscopy, mammography and low-dose lung CT screen for cancer.
- Measure your health today. Cholesterol, blood sugar and kidney function come from a blood panel.
- Say when, or whether, a common disease will start. NHGRI says risk scores are probabilities, not certainties, and give no timeframe.
- Clear you. ACMG warns that a negative DNA screen can give false reassurance. Family history still counts; the genetic testing page explains why.
- Explain a variant of uncertain significance. Nobody can yet, as the box below sets out.
Who is it for, and who should think twice?
| Your situation | What the guidance suggests |
|---|---|
| A personal or family history that suggests an inherited condition | See a genetic counselor first. ACMG says DNA screening should not replace the standard evaluation for someone with a reason to be tested. |
| Planning a pregnancy | ACMG recommends offering carrier screening. Check that the report covers SMN1 and the alpha-thalassemia genes. |
| Taking, or likely to need, a medicine with a known gene-drug pair | A gene-drug result can guide the prescriber for the pairs the FDA lists. Show the report to every prescriber. |
| Healthy and curious, with no family history | Evidence of benefit is limited. MedSeq found genome results in healthy adults to be of uncertain clinical value. |
| About to apply for life, disability or long-term-care insurance | US federal law does not protect genetic information in these policies. Check your state's law before you test. |
| Hoping to learn whether you have cancer now | WGS cannot answer that. Use the cancer screening proven for your age. |
Why have genetic counseling before and after?
The US National Cancer Institute generally recommends genetic counseling before testing for inherited cancer risk. It adds that counseling may follow the test, especially after a positive result. A counselor covers:
- Before: your family history, what you want reported, whether you want secondary findings, and the insurance and privacy points below.
- After: what each finding means, which ones call for action, how screening changes, and which relatives to tell.
Your coordinator confirms who explains the report at iHope Clinic, in which language, and whether that is included. In the US, the National Society of Genetic Counselors runs a "Find a Genetic Counselor" directory that includes counselors who meet by phone or video.
Who can see your genome, and what does the law protect?
Your genome is personal data about you and, in part, about your blood relatives. Protection depends on the law where you live and where the data is held:
| Law | What it protects | Limits |
|---|---|---|
| US Genetic Information Nondiscrimination Act (GINA, 2008) | Health insurers and employers may not use your genetic information against you | Life, disability and long-term-care insurance; employers with fewer than 15 employees; the US military |
| US state laws | Some states extend protection to life, disability or long-term-care insurance | Coverage differs from state to state; check yours |
| Taiwan Personal Data Protection Act, Article 6 | Genetic data may be collected, processed or used only on listed grounds, such as your written consent | Consent does not cover use beyond the necessary scope of its stated purpose; other grounds exist, such as de-identified academic or public-health research |
Questions to ask about your data
- Where are the sample and the data stored, and for how long?
- Who can access them, and are they used for research?
- Can you get a copy of your raw data files, and in what format?
- Can you ask for the sample and the data to be destroyed?
What happens on the day?
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1ConsentYou confirm what you want reported, including whether you want secondary findings. Your coordinator confirms whether a counselor or physician meets you first.
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2The sampleGenetic tests use a sample such as blood or a cheek swab. The sample type and any preparation for these packages are confirmed when you book.
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3You leaveOur booking record lists 30 minutes for either package. The sample then goes to the laboratory.
The physical step is minor. The risks that matter come from what you learn: uncertain results, follow-up tests of unclear value, and the insurance gaps above.
When do results arrive, and what if something is found?
MedlinePlus says genetic results can take a few days to weeks from the day the sample is taken. The turnaround for these packages is confirmed by the clinic when you book.
Before you leave Taiwan
- Get the full report in English. Taiwan's Medical Care Act, Article 71, requires a clinic to provide a copy of your records on request. The law allows a Chinese summary, so ask for English specifically.
- Check that each finding is fully described. The report should name the gene, the exact change and its classification.
- Ask for your raw data files, if the clinic provides them.
Back home with a finding
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1Book a genetic counselorThe National Society of Genetic Counselors directory lists counselors who meet in person or by video.
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2Confirm the variantACMG says clinical genetic testing should be done in a CLIA-approved laboratory, so your doctor may repeat the key variant in one before acting on it.
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3Follow the plan for that conditionACMG says follow-up should match the best practice of the relevant specialty society. For example, the American Cancer Society advises a yearly breast MRI and mammogram, typically from age 30, for women with a BRCA1 or BRCA2 change.
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4Tell your blood relativesA person with a dominant variant has a 50% chance of passing it to each child. Relatives can then decide on their own testing.
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5Leave uncertain results aloneDo not change your care because of a variant of uncertain significance. Ask the laboratory whether it will tell you if the variant is reclassified.
How much does it cost, and will insurance pay?
The live prices further down this page are the booking prices at New Dawn Health for both packages. Care after you fly home, such as counseling or a confirmation test, is arranged and paid for at home.
- Screening in Taiwan is self-funded for visitors. Short-term visitors are not covered by Taiwan's National Health Insurance.
- Reimbursement at home is a question for your insurer. The National Cancer Institute advises discussing cost and coverage with your insurer before testing.
