a new approach for pairwise kinship analysis in forensic genetics based on chromosomal sharing between two individuals. Here, we defined “index of chromosome sharing” (ICS) calculated using 174,254 single nucleotide polymorphism (SNP) loci typed by SNP microarray and genetic length of the shared segments from the genotypes of two individuals. To investigate the expected ICS distributions from first- to fifth-degree relatives and unrelated pairs, we used computationally generated genotypes to consider the effect of linkage disequilibrium and recombination. The distributions were used for probabilistic evaluation of the pairwise kinship analysis, such as likelihood ratio (LR) or posterior probability, without allele frequencies and haplotype frequencies. Using our method, all actual sample pairs from volunteers showed significantly high LR values (i.e., ≥ 108); therefore, we can distinguish distant relationships (up to the fifth-degree) from unrelated pairs based on LR. Moreover, we can determine accurate degrees of kinship in up to third-degree relationships with a probability of > 80% using the criterion of posterior probability ≥ 0.90, even if the kinship of the pair is totally unpredictable. This approach greatly improves pairwise kinship analysis of distant relationships, specifically in cases involving identification of disaster victims or missing persons.

1. PAIRWISE KINSHIP ANALYSIS
BY THE INDEX OF CHROMOSOME SHARING USING SINGLE NUCLEOTIDE POLYMORPHISM
BY :
PARTH CHAUHAN
BSc. (H) Forensic Science
Amity University , Gurgaon , India

2. “The aim to find a new approach of doing Kinship analysis up to 5th degree
relationship between two individuals in a population or a society.”
WHY TO RESEARCH
NEED TO PERFORM RESEARCH -
• In current forensic case work, Paternity analysis and forensic DNA -
typing using 15 STR loci is used which detect only 1st degree relationship
between individuals .
• Lacking in identification of relationships beyond Parent-child or child-
sibling .
• In case of wide area disaster for e.g. FLOOD, CYCLONE, etc. 1st degree of
kinship analysis is insufficient.

3. Table defining the degree of relationship basically 1st, 2nd, 3rd and 4th degree relatives

4. METHODS OF FINDING KINSHIP BETWEEN THE INDIVIDUALS
ARE -
LR is the Likelihood Ratio that a given test result
could be expected in a patient with target disorder Compared to the
likelihood that the same result would be expected in a patient without the
target disorder.
LIKELIHOOD RATIO :-
POSTERIOR PROBABILITY :-
The revised probability of an event occurring after
taken into consideration new information.

5. GADGETS USED :
• Human core-12/24 bead chip used for
DNA microarray in human genome with
2304 samples at a time.
• DNA Isolation and Stabilization kits,
enables high yields of pure, intact DNA
to be collected easily and quickly.

6. A GLIMPSE ON SNP
• Are found in coding (mostly) and
non coding regions.
• The abundance of SNP and ease
with which they can be measured
make these genetic variation
significant.
• SNPs close to particular gene act
as marker for that gene.
• SNPs in coding region may alter
the protein structure made by
the coding region.

7. PROCESSING
1. DNA extraction from individuals (taken two as a pair).
2. SNP typing by SNP microarray giving 174,254 SNPs
3. Investigating the IBS segment
4. Formation of Index By Chromosome Sharing (ICS).
5. Genetic length prediction
6. Kinship prediction by methods above.

8. THE ICS BETWEEN INDIVIDUAL PAIRS
• ICSc and ICSl termed as ICS for collateral relatives and ICS for lineal relatives .
• The threshold value (Th) for C-Th and L-Th taken as 4cM and 3cM respectively.
• Calculated the ics(Th) values from computationally generated genotypes from the
survey of 249 families and taken half of the ICS values in the chart into
consideration.
• C-1 is siblings ,C-2 is uncle-nephew, C-3 is first cousin, C-4 is first cousin once
removed and C-2 is second cousin and three types of L relationships are parent-
child(L-1), grandparent –grandchild(L-2) and great grandparent – great
grandchild(L-3).
• They also taken 15 UN pairs for a sample to analyze .

9. REFERENCES
• Pairwise Kinship Analysis by the Index of Chromosome Sharing Using High-
Density Single Nucleotide Polymorphisms -
http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0160287
• Likelihood Ratio - https://www.cebm.net/2014/02/likelihood-ratios/
• Posterior Probability - https://www.investopedia.com/terms/p/posterior-
probability.asp
• Human core Bead chips - https://www.illumina.com/products/by-
type/microarray-kits/infinium-core.html
• DNA buccal swabs -http://www.isohelix.com/products/isohelix-dna-buccal-
swabs/?gclid=Cj0KCQiA2Y_UBRCGARIsALglqQ2x9w6QZb16i8DAuHnKiHnFyZ_-
vnb1K4rsM0q1ayY7wSGzLZsrTDMaArwtEALw_wcB
• SNP - https://www.slideshare.net/chandanhaldar750/snp-47788728

10. THANK
YOU