This document summarizes a study that used the BigLD algorithm to partition haplotype blocks in chromosome 21 of the NARAC genomic dataset. The researchers:
1) Applied the BigLD algorithm and three other methods (FGT, CIT, SSLD) to detect haplotype blocks in a portion of chromosome 21.
2) Analyzed and compared the blocks detected by each method based on parameters like block size, number of blocks, and genomic coverage.
3) Found that BigLD produced the fewest and largest blocks, indicating more robust partitioning compared to the other methods.
1. Minia University
Faculty of Engineering
Biomedical Engineering Department
Haplotype Block Partitioning for
NARAC Dataset Using Interval Graph
Modeling of Clusters Algorithm
Authors:
Fatma S. Ibrahim
Mohamed N. Saad
Ashraf M. Said
Hesham F. A. Hamed
8. Extracting
Chromosome
21 from entire
NARAC genomic
dataset
NARAC 22 chromosomes input files
NARAC genomic data
(2,062 individuals)
Perl
Choosing chromosome
21 under study
Genotyped
ch21 dataset
Map file for
ch21
NARAC map file
(545,080 SNPs)
R
Chromosomes
separated data
Chromosomes
separated map file
8
9. System
description
start
NARAC genotype
dataset ch21
NARAC map file
Position ch21
Reformatting Data for
codeGeno function
Imputation of missing data
Biomarker check
Recoding to 0,1,2
Genotype format
Processed
Genotype data
Applying Big-LD algorithm
Haplotype blocks
Plotting the heatmap
Calculating the parameters of the blocks
and make the comparison among methods
9
10. System
description
start
NARAC genotype
dataset ch21
NARAC map file
Position ch21
Reformatting Data for
codeGeno function
Imputation of missing data
Biomarker check
Recoding to 0,1,2
Genotype format
Processed
Genotype data
Applying Big-LD algorithm
Haplotype blocks
Plotting the heatmap
Calculating the parameters of the blocks
and make the comparison among methods
BigLD
SSLD
CIT
FGT
10
12. Blocks features and
parameters
Haplotype block portioning
based on BigLD method
Pre-processing phase 2
(recoding)
Pre-processing phase 1
(reformatting)
Reading and cropping
The steps of haplotype block partitioning based on BigLD
method
12
13. Heatmap for the haplotype
blocks detected by interval
graph modeling of clusters for a
portion of chromosome 21 from
9,993,822 bp to 14,137,685 bp.
13
17. 17
• Big-LD method provided robust blocks partitioning in terms of the
block size and genomic coverage.
• Moreover, it produced the least total number of blocks compared to
CIT, FGT, and SSLD.
• Big-LD produces larger LD blocks compared to other existing
methods
17
18. 18
• The results showed the similar intersections and inconsistencies among
resulted blocks.
• This analysis shows that Big-LD matched more with FGT and produced much
more stable large haplotype blocks for NARAC dataset
18
Editor's Notes
I've organized my talk into eight topics shown here.
SNP: single base mutation in DNA
Therefore, Haplotype block partitioning is important for population genetics, association analysis, and genetic epidemiology
This research provided an empirical comparison of haplotype blocks partitioned by four different methods for chromosome 21 of the NARAC dataset
The proposed analysis demonstrated the differences and similarities among the most common four methods of haplotype partitioning. This analysis shows that Big-LD matched more with FGT and produced much more stable large haplotype blocks for NARAC dataset