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Updated: Jun 19, 2026

Rare Event Detection Using Error-corrected DNA and RNA Sequencing
Published on: August 3, 2018
Single nucleotide differences (SNDs) in the dbSNP database may lead to errors in genotyping and haplotyping studies
Lucia Musumeci1, Jonathan W Arthur, Florence S G Cheung
1Plunkett Chair of Molecular Biology (Medicine), Bosch Institute, The University of Sydney, Medical Foundation Building (K25), Camperdown, NSW 2006, Australia.
Many reported single nucleotide polymorphism (SNP) database entries are actually artifacts called single nucleotide differences (SNDs) caused by duplicated genes. Identifying these SNDs improves SNP accuracy for genetic research.
Area of Science:
- Genomics
- Bioinformatics
- Human Genetics
Background:
- Single nucleotide polymorphism (SNP) databases are crucial for genetic research.
- Existing SNP databases, like NCBI dbSNP, contain millions of entries but suffer from inaccuracies.
- A significant portion of reported SNPs are unvalidated candidate SNPs.
Purpose of the Study:
- To identify and characterize single nucleotide differences (SNDs) that contaminate human SNP databases.
- To investigate the origin of SNDs as artifacts arising from paralogous sequences.
- To estimate the prevalence of SNDs within the dbSNP database.
Main Methods:
- Utilized sequencing to demonstrate SND formation in paralogous genes.
- Evaluated 100 human individuals to assess SNP and SND presence.
- Employed bioinformatics tools to predict SNDs in coding SNPs within dbSNP.
Main Results:
- Identified single nucleotide differences (SNDs) as artifacts, not true SNPs, originating from paralogous sequences.
- Demonstrated that SNDs can arise from duplicated gene regions.
- Predicted that 8.32% of biallelic, coding SNPs in dbSNP may be SNDs.
Conclusions:
- The presence of SNDs compromises the accuracy of SNP databases.
- Researchers can now better select validated SNPs for association studies.
- Improved SNP data quality will enhance accurate SNP genotyping and haplotyping.
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