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Updated: Jun 23, 2026
09:45
Detection of Copy Number Alterations Using Single Cell Sequencing
Published on: February 17, 2017
A Bayesian segmentation approach to ascertain copy number variations at the population level
Long Yang Wu1, Hugh A Chipman, Shelley B Bull
1Department of Statistics and Actuarial Science, University of Waterloo, Waterloo, Ontario, Canada. lwu@math.uwaterloo.ca
Bioinformatics (Oxford, England)
|April 25, 2009
Summary
A new Bayesian segmentation approach efficiently identifies copy number variations (CNVs) in populations. This method simultaneously segments data and assigns copy numbers, outperforming existing methods in simulations and real-world data analysis.
Area of Science:
- Genetics
- Bioinformatics
- Computational Biology
Background:
- Accurate copy number variation (CNV) identification is crucial for understanding population genetics and complex diseases.
- Current methods for CNV detection have limitations in population-level analysis and simultaneous segmentation/copy number assignment.
- Population-level CNV data is essential for evolutionary studies and genome-wide association studies (GWAS).
Purpose of the Study:
- To develop a novel, computationally efficient Bayesian segmentation approach for identifying CNVs at the population level.
- To simultaneously perform segmentation and copy number status assignment for CNVs.
- To provide statistical evidence for detected CNVs using the Bayes factor.
Main Methods:
- A novel Bayesian segmentation approach is proposed.
- The method performs segmentation and copy number assignment simultaneously.
- Statistical evidence for CNVs is provided through the Bayes factor.
Main Results:
- The new approach demonstrates competitive performance in breakpoint detection (false discovery rate and sensitivity) compared to popular two-step methods in single-individual simulations.
- Outperforms leading single-sample methods in multi-sample simulations with recurrent copy numbers.
- Effectively applied to population-level analysis of HapMap data and for studying CNV population genetics.
Conclusions:
- The proposed Bayesian segmentation approach is efficient and accurate for population-level CNV identification.
- The simultaneous segmentation and copy number assignment feature offers an advantage over existing methods.
- The approach is valuable for population genetics research and GWAS of complex human diseases.
Related Concept Videos
02:26Comparing Copy Number Variations and SNPs
Sequencing of the human genome has opened up several best-kept secrets of the genome. Scientists have identified thousands of genome variations that exist within a population. These variations can be a single nucleotide or a larger chromosomal variation.
Copy number variations or CNVs are the structural variations that cover more than 1kb of DNA sequence. The single nucleotide polymorphism (SNP), on the other hand, is a single nucleotide change or a point mutation that is found in more than 1%...
Copy number variations or CNVs are the structural variations that cover more than 1kb of DNA sequence. The single nucleotide polymorphism (SNP), on the other hand, is a single nucleotide change or a point mutation that is found in more than 1%...
01:05Single Nucleotide Polymorphisms-SNPs
A single nucleotide polymorphism or SNP is a single nucleotide variation at a specific genomic position in a large population. It is the most prevalent type of sequence variation found in the human genome. Point mutations that occur in more than 1% of the population qualify as SNPs. These are present once every 1000 nucleotides on an average in the human genome. Replacement of a purine with another purine (A/G) or a pyrimidine with another pyrimidine (C/T) is known as a transition. In contrast,...
02:46Genome Copying Errors
DNA replication is a well-evolved process that copies millions of base pairs with high fidelity during each cell division. Occasionally a wrong base or a long stretch of wrong bases may get added to the daughter strands. If the errors are left unchecked, cells might accumulate several mutations that might endanger their survival. Therefore, the copying errors are checked and repaired at three levels.
02:37Gene Duplication and Divergence
The seminal work of Ohno in 1970 popularized the idea of gene duplication and divergence. DNA sequence comparison studies reveal that a large portion of the genes in bacteria, archaebacteria, and eukaryotes was generated by gene duplication and divergence, indicating its critical role in evolution.
The duplicated copies of the gene are called Paralogs. Paralogs with similar sequences and functions form a gene family. Across several species, a large number of gene families are characterized.
The duplicated copies of the gene are called Paralogs. Paralogs with similar sequences and functions form a gene family. Across several species, a large number of gene families are characterized.
01:25Genetic Variation
Genetic variation is the diversity in DNA sequences found among individuals of the same species. This diversity is crucial for a species' survival because it helps organisms adapt to environmental changes. Genetic variation begins with fertilization, where an egg and sperm cell merge. Each of these cells carries 23 chromosomes, up to 46 in the fertilized egg. Chromosomes are long DNA strands that contain genes, the basic units of heredity.
Genes exist in different versions called alleles, which...
Genes exist in different versions called alleles, which...
01:11Genome-wide Association Studies-GWAS
Genome-wide association studies or GWAS are used to identify whether common SNPs are associated with certain diseases. Suppose specific SNPs are more frequently observed in individuals with a particular disease than those without the disease. In that case, those SNPs are said to be associated with the disease. Chi-square analysis is performed to check the probability of the allele likely to be associated with the disease.
GWAS does not require the identification of the target gene involved in...
GWAS does not require the identification of the target gene involved in...