Title
Approximation properties of haplotype tagging.
Abstract
Background: Single nucleotide polymorphisms (SNPs) are locations at which the genomic sequences of population members differ. Since these differences are known to follow patterns, disease association studies are facilitated by identifying SNPs that allow the unique identification of such patterns. This process, known as haplotype tagging, is formulated as a combinatorial optimization problem and analyzed in terms of complexity and approximation properties. Results: It is shown that the tagging problem is NP-hard but approximable within 1 + ln((n2 - n)/ 2) for n haplotypes but not approximable within (1 - ε) ln(n/2) for any ε > 0 unless NP ⊂ DTIME(nlog log n). A simple, very easily implementable algorithm that exhibits the above upper bound on solution quality is presented. This algorithm has running time O (( 2m - p + 1)) ≤ O(m(n2 - n)/2) where p ≤ min(n, m) for n haplotypes of size m. As we show that the approximation bound is asymptotically tight, the algorithm presented is optimal with respect to this asymptotic bound. Conclusion: The haplotype tagging problem is hard, but approachable with a fast, practical, and surprisingly simple algorithm that cannot be significantly improved upon on a single processor machine. Hence, significant improvement in computatational efforts expended can only be expected if the computational effort is distributed and done in parallel.
Year
DOI
Venue
2006
10.1186/1471-2105-7-8
BMC Bioinformatics
Keywords
Field
DocType
sequence alignment,approximation property,haplotypes,upper bound,single nucleotide polymorphism,bioinformatics,computational biology,genome sequence,algorithms,microarrays
Sequence alignment,Approximation algorithm,Population,Biology,Haplotype,Single-nucleotide polymorphism,Bioinformatics,Genetics,Time complexity,DNA microarray,Polynomial-time reduction
Journal
Volume
Issue
ISSN
7
1
1471-2105
Citations 
PageRank 
References 
21
0.37
5
Authors
3
Name
Order
Citations
PageRank
Staal Vinterbo136132.66
Stephan Dreiseitl233834.80
Lucila Ohno-Machado31426187.95