Evidence map›Paper›PMID 22549150›Full record

ArticleBMC medical genomics2012

Evaluation of the imputation performance of the program IMPUTE in an admixed sample from Mexico City using several model designs.

S Krithika, Adán Valladares-Salgado, Jesus Peralta, Jorge Escobedo-de La Peña, Jesus Kumate-Rodríguez, Miguel Cruz, Esteban J Parra

Abstract readEvaluation Study
In one paragraph

Article in BMC medical genomics, 2012. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 8 papers.

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8citing papers in PubMed
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3 · Its place in the literature

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8 citing papers in PubMed.

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4 · The record

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5 · Who and what money

Authors and funding

7 authors.

S KrithikaDepartment of Anthropology, University of Toronto at Mississauga, 3359 Mississauga Road North, Mississauga, ON, Canada.
Adán Valladares-Salgado
Jesus Peralta
Jorge Escobedo-de La Peña
Jesus Kumate-Rodríguez
Miguel Cruz
Esteban J Parra

Funding

Canadian Institutes of Health Research
6 · The paper itself

Abstract

backgroundWe explored the imputation performance of the program IMPUTE in an admixed sample from Mexico City. The following issues were evaluated: (a) the impact of different reference panels (HapMap vs. 1000 Genomes) on imputation; (b) potential differences in imputation performance between single-step vs. two-step (phasing and imputation) approaches; (c) the effect of different INFO score thresholds on imputation performance and (d) imputation performance in common vs. rare markers.

methodsThe sample from Mexico City comprised 1,310 individuals genotyped with the Affymetrix 5.0 array. We randomly masked 5% of the markers directly genotyped on chromosome 12 (n=1,046) and compared the imputed genotypes with the microarray genotype calls. Imputation was carried out with the program IMPUTE. The concordance rates between the imputed and observed genotypes were used as a measure of imputation accuracy and the proportion of non-missing genotypes as a measure of imputation efficacy.

resultsThe single-step imputation approach produced slightly higher concordance rates than the two-step strategy (99.1% vs. 98.4% when using the HapMap phase II combined panel), but at the expense of a lower proportion of non-missing genotypes (85.5% vs. 90.1%). The 1,000 Genomes reference sample produced similar concordance rates to the HapMap phase II panel (98.4% for both datasets, using the two-step strategy). However, the 1000 Genomes reference sample increased substantially the proportion of non-missing genotypes (94.7% vs. 90.1%). Rare variants (<1%) had lower imputation accuracy and efficacy than common markers.

conclusionsThe program IMPUTE had an excellent imputation performance for common alleles in an admixed sample from Mexico City, which has primarily Native American (62%) and European (33%) contributions. Genotype concordances were higher than 98.4% using all the imputation strategies, in spite of the fact that no Native American samples are present in the HapMap and 1000 Genomes reference panels. The best balance of imputation accuracy and efficiency was obtained with the 1,000 Genomes panel. Rare variants were not captured effectively by any of the available panels, emphasizing the need to be cautious in the interpretation of association results for imputed rare variants.

Indexed as

HapMap ProjectModels, StatisticalSoftwareGene FrequencyGenetic MarkersGenome, HumanGenotyping TechniquesHumansMexicoOligonucleotide Array Sequence AnalysisReference StandardsGenetic Markers

Identifiers

PMID22549150
PMCPMC3436779

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Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.