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Published on: October 20, 2019
Noninvasive prenatal molecular karyotyping from maternal plasma
Stephanie C Y Yu1, Peiyong Jiang, Kwong W Choy
1Centre for Research into Circulating Fetal Nucleic Acids, Li Ka Shing Institute of Health Sciences, The Chinese University of Hong Kong, Shatin, New Territories, Hong Kong SAR, China.
Noninvasive prenatal karyotyping using massively parallel sequencing of maternal plasma DNA can now detect fetal microdeletions and microduplications across the whole genome. This advanced molecular karyotyping enhances the diagnostic capabilities of noninvasive prenatal testing.
Area of Science:
- Genetics
- Molecular Biology
- Prenatal Diagnostics
Background:
- Maternal plasma contains cell-free fetal DNA, enabling noninvasive prenatal testing.
- Previous methods for detecting fetal chromosomal abnormalities were limited in scope or resolution.
- Detecting microdeletions and microduplications noninvasively has been challenging.
Purpose of the Study:
- To develop and validate a whole-genome noninvasive prenatal molecular karyotyping method using massively parallel sequencing.
- To achieve a diagnostic resolution of 3 Mb across the entire genome.
- To expand the range of detectable fetal genetic abnormalities beyond aneuploidies.
Main Methods:
- Massively parallel sequencing of maternal plasma DNA.
- Analysis of plasma DNA to perform whole-genome noninvasive prenatal karyotyping.
- Simulation analyses to determine sequencing depth for higher resolution (2 Mb and 1 Mb).
Main Results:
- Successfully detected fetal microdeletions in 3 out of 6 cases.
- Successfully detected fetal microduplications in 2 out of 6 cases.
- Identified one case where the mother was a carrier of a microduplication.
Conclusions:
- Noninvasive prenatal molecular karyotyping from maternal plasma via massively parallel sequencing is feasible.
- This method significantly enhances the diagnostic spectrum of noninvasive prenatal testing.
- The technique offers a high-resolution, whole-genome approach for detecting fetal copy number variations.
