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Updated: Apr 7, 2026
Detection of Copy Number Alterations Using Single Cell Sequencing
Published on: February 17, 2017
Accurate Detection of Multiple Chromosome Rearrangements and Copy Number Variations by PacBio Sequencing in Complex
Lili Liu1, Kai Kang2, Hao Wang3
1Medical Genetic Laboratory, Shenyang JingHua Hospital, Shenyang, Liaoning, China.
Objective:
Accurate detection is crucial for achieving healthy live births in families with complex chromosomal balanced translocations (CCBTs). Application of PacBio technology to investigate the chromosomal characteristics of a rare family with CCBTs involving multiple chromosomes.
Method:
We investigated a family with a history of four miscarriages who underwent assisted reproduction. Whole-genome sequencing using the PacBio platform was performed to precisely locate translocation breakpoints, and bioinformatic results were further validated by optical genome mapping (OGM) and copy number variation sequencing (CNV-seq).
Results:
The male partner was originally diagnosed by karyotyping as 46,XY,t(8; 9) (q11.2; p24), and by fluorescence in situ hybridization (FISH) as ish der(8) (8pter-,8qter-,9pter+,11qter+),der(9) (8qter+,9pter-),der(11) (8pter+,11qter-). However, PacBio sequencing revealed additional complexity, identifying 12 breakpoints in total and enabling the reconstruction of derived chromosomes. The rearrangement of complex and minute chromosomal fragments resulted in multiple abnormal derivative chromosomes. PacBio sequencing also assessed CNVs and found no pathogenic alterations. All findings were confirmed by OGM and CNV-seq, with PacBio providing more comprehensive breakpoint information than either method alone.
Conclusion:
This study reports a rare CCBT involving three chromosomes and 12 breakpoints, underscoring the high-resolution capability of PacBio sequencing for precise breakpoint mapping and its potential for improving the detection and characterization of CCBTs in clinical practice.
