Evidence map›Paper›PMID 25888400›Full record

ArticleBMC genomics2015

Combinatorial Conflicting Homozygosity (CCH) analysis enables the rapid identification of shared genomic regions in the presence of multiple phenocopies.

Adam P Levine, Thomas M F Connor, D Deren Oygar, Guy H Neild, Anthony W Segal, Patrick H Maxwell, Daniel P Gale

Abstract read
In one paragraph

Article in BMC genomics, 2015. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 4 papers.

0numbers the graph read from it
0cells of the map it votes in
4citing papers in PubMed
–field-weighted citation impact
1 · What the graph read from it

What it found

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The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.

2 · The registry

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3 · Its place in the literature

Who cites it

4 citing papers in PubMed.

  1. Article
  2. Article
  3. A novel COL4A1 frameshift mutation in familial kidney disease: the importance of the C-terminal NC1 domain of type IV collagen.Nephrology, dialysis, transplantation : official publication of the European Dialysis and Transplant Association - European Renal Association · 2016
    Article
  4. Article
4 · The record

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5 · Who and what money

Authors and funding

7 authors.

Adam P LevineDivision of Medicine, University College London, London, UK. a.levine@ucl.ac.uk.
Thomas M F ConnorDivision of Medicine, University College London, London, UK. t.connor@alumni.ucl.ac.uk.
D Deren OygarNicosia State Hospital, Burhan Nalbantoğlu State Hospital, Nicosia, North Cyprus. derenoygar@yahoo.com.
Guy H NeildDivision of Medicine, University College London, London, UK. g.neild@ucl.ac.uk.
Anthony W SegalDivision of Medicine, University College London, London, UK. t.segal@ucl.ac.uk.
Patrick H MaxwellSchool of Clinical Medicine, Cambridge University, Cambridge, UK. phm29@medschl.cam.ac.uk.
Daniel P GaleDivision of Medicine, University College London, London, UK. d.gale@ucl.ac.uk.

Funding

Medical Research Council G0802266Medical Research Council G1002528Medical Research Council MR/L000261/1Wellcome Trust 100140
6 · The paper itself

Abstract

backgroundThe ability to identify regions of the genome inherited with a dominant trait in one or more families has become increasingly valuable with the wide availability of high throughput sequencing technology. While a number of methods exist for mapping of homozygous variants segregating with recessive traits in consanguineous families, dominant conditions are conventionally analysed by linkage analysis, which requires computationally demanding haplotype reconstruction from marker genotypes and, even using advanced parallel approximation implementations, can take substantial time, particularly for large pedigrees. In addition, linkage analysis lacks sensitivity in the presence of phenocopies (individuals sharing the trait but not the genetic variant responsible). Combinatorial Conflicting Homozygosity (CCH) analysis uses high density biallelic single nucleotide polymorphism (SNP) marker genotypes to identify genetic loci within which consecutive markers are not homozygous for different alleles. This allows inference of identical by descent (IBD) inheritance of a haplotype among a set or subsets of related or unrelated individuals.

resultsA single genome-wide conflicting homozygosity analysis takes <3 seconds and parallelisation permits multiple combinations of subsets of individuals to be analysed quickly. Analysis of unrelated individuals demonstrated that in the absence of IBD inheritance, runs of no CH exceeding 4 cM are not observed. At this threshold, CCH is >97% sensitive and specific for IBD regions within a pedigree exceeding this length and was able to identify the locus responsible for a dominantly inherited kidney disease in a Turkish Cypriot family in which six out 17 affected individuals were phenocopies. It also revealed shared ancestry at the disease-linked locus among affected individuals from two different Cypriot populations.

conclusionsCCH does not require computationally demanding haplotype reconstruction and can detect regions of shared inheritance of a haplotype among subsets of related or unrelated individuals directly from SNP genotype data. In contrast to parametric linkage allowing for phenocopies, CCH directly provides the exact number and identity of individuals sharing each locus. CCH can also identify regions of shared ancestry among ostensibly unrelated individuals who share a trait. CCH is implemented in Python and is freely available (as source code) from http://sourceforge.net/projects/cchsnp/ .

Indexed as

Genes, DominantPhenotypeAlgorithmsGenetic LinkageGenomicsGenotypeHomozygoteHumansKidney DiseasesLinkage DisequilibriumPedigreePolymorphism, Single NucleotideRecombination, Genetic

Identifiers

PMID25888400
PMCPMC4364077

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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.