1. Comparison table of core differences
|
detection type |
detection range |
technical characteristics |
applicable scenarios |
|
non-invasiveDNA |
Limited to3common trisomies: 21-trisomy (Down's)18-trisomy13-trisomy |
Standard sequencing depth, false positive rate< 0.5% |
Basic screening needs, those with limited budgets |
|
Non-invasivePLUS |
Chromosome level expansion: - 3trisomy+sex chromosome abnormalities (e.g.Turnersyndrome) - 76microdeletion/microduplication syndromes (such asDiGeorgesyndrome, cat barking syndrome) |
The depth of sequencing has been improved, and the detection rate of microdeletions is>90% |
People who wish to conduct a comprehensive screening for chromosomal abnormalities and have no family history of monogenic diseases |
|
Non-invasivePRO |
Breakthroughs at the genetic level: - PLUSAll content+ 92monogenic dominant diseases (such asRettsyndrome, neurofibromatype1) |
Ultra-deep sequencing (>800×)+molecular tagging technology, sensitivity>99% |
Elderly parents, people worried about single gene diseases or rare diseases |
2. In-depth analysis of technical principles and screening capabilities
1. Non-invasiveDNA: A "precise sniper" for chromosome abnormalities·Detection of chromosomal number abnormalities by fetal free DNA in the blood of pregnant women (5% of maternal blood DNA).
·Advantages: The detection rate for trisomy 21 is>99%, trisomy 18 is>96%, and trisomy 13 is>92%, which is much higher than that of traditional Tang screening (false positive rate 5%).
Limitations: Covering only 0.1% of known genetic disease types.
2. Non-invasive PLUS: A "panoramic scan" of chromosome structure
·Expand to chromosome fragment level abnormalities: Deletions/duplications of> 10Mb can be detected (e.g. 22q11.2 microdeletion causes DiGeorge syndrome).
·Clinical significance: The total incidence of microdeletion syndrome reaches 1%-1.7%. Although children can survive, most of them are accompanied by congenital malformations or intellectual impairment.
3. Non-invasive PRO: The "non-invasive diagnostic revolution" for single gene diseases
·Core breakthrough: Simultaneous screening of 92 dominant monogenic diseases, 75% of which were new mutations (parents had normal genes).
·Technical support:
③ Molecular labeling technology prevents experimental errors and avoids false negatives
③ Ultra-deep sequencing captures low-frequency mutations (such as mutations in the MECP2 gene in Rett syndrome).
·Typical diseases:
Achondroplasia: The limbs are short during the fetal period, which is easy to miss by ultrasound
Noonan syndrome: Postnatal growth delay, congenital heart disease.
3. Applicable groups and decision-making guidelines
Commonly applicable conditions·Pregnancy week: 12-22 weeks (appropriate window)
·Operation: Draw 10ml of blood without fasting
·Applicable population:
Tang screening critical risk, missing serological screening
Sheep wear contraindications (such as threatened abortion, Rh-negative blood).
Differential selection suggestions
detection type
Prioritize groups
Use with caution/not applicable
non-invasiveDNA
Young pregnant women, only concerned about three major chromosome diseases, with limited budgets
Advanced age (≥35years), obesity (BMI> 40), multiple pregnancy
Non-invasivePLUS
Want to exclude people with a high incidence of microdeletion syndrome (such asDiGeorge)
Same as non-invasiveDNAand attention should be paid to the reduced accuracy of twin testing
Non-invasivePRO
Elderly parents (fathers>40years old are at risk of new mutations ↑), people worried about rare diseases
Only for single births, and family history of genetic diseases is not applicable
4. Interpretation of results and matters needing attention
1. Low risk ≠ complete health·All non-invasive tests are screening in nature and there is a very small possibility of false negatives (e.g., PRO has a sensitivity of 99% for monogenic diseases)
·Continuous monitoring needs to be combined with ultrasound (such as NT, large row deformity).
2. High risks must be diagnosed
·Even if non-invasive PRO indicates a high risk, it must be confirmed through amniotic fluid puncture + gene chip/sequencing
·Sheep wearing remains the "gold standard" for the diagnosis of chromosomal/genetic diseases.
3. technical limitations
·Inability to detect recessive genetic diseases (pre-pregnancy carrier screening is required)
·Mixing of fetal DNA in multiple pregnancies may interfere with results.
5. Summary: Three steps of scientific selection
1. Clarify needs·Basic needs → Select non-invasive DNA
·Worried about chromosomal fragment abnormalities → Choose PLUS
·Advanced age or concern about a single gene disease → Select PRO.
2. Assess your own risks
Age, pregnancy history, and family genetic background are key decision-making factors.
3. Combination strategies maximize protection
·Ideal solution: non-invasive PRO (12 weeks)+ systematic ultrasound (20-24 weeks)+ sheep wear when necessary
·Three steps of prevention: pre-pregnancy genetic screening → non-invasive during pregnancy + ultrasound → postpartum neonatal metabolic screening.
Note:Any test must be selected under the guidance of a genetic doctor.
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