Formula Derivation for the Probability Distribution of IBS Score in Unrelated Individual Pairs.
Fa Yi Xue Za Zhi
; 34(4): 370-374, 2018 Aug.
Article
in En, Zh
| MEDLINE
| ID: mdl-30465400
ABSTRACT
OBJECTIVES:
To derive the probability equation given by STR allele frequencies of identity by state ï¼IBSï¼ score shared by unrelated individual pairs.METHODS:
By comparing the STR genotypes of two unrelated individuals, three mutually exclusive combinations could be obtainedï¼ ï¼1ï¼ sharing 2 identical alleles, a2=1, otherwise a2=0; ï¼2ï¼ sharing 1 identical allele, a1=1, otherwise a1=0; ï¼3ï¼ sharing 0 identical allele, a0=1, otherwise a0=0. And the IBS score of the one STR locus in this unrelated individual pair could be given by the formulaï¼ ibs=2a2+a1. The probability of a2=1 ï¼p2ï¼, a1=1 ï¼p1ï¼ and a0=1 ï¼p0ï¼ were derived and expressed in powers of the allele frequencies. Subsequently, for a genotyping system including n independent STR loci, the characteristics of binomial distribution of IBS score shared by a pair of unrelated individuals could be given by p2l and p1l ï¼l=1, 2, , nï¼.RESULTS:
All the general equations of p2, p1 and p0 were derived from the basic conceptions of a2, a1 and a0, respectively. Given fi ï¼i=1, 2, , mï¼ as the ith allele frequency of a STR locus, the general equations of p2, p1 and p0 could be respectively expressed in powers of fiï¼ [Formula see text],[Formula see text] and [Formula see text]. The sum of p2, p1 and p0 must be equal to 1. Then, the binomial distribution of IBS score shared by unrelated individual pairs genotyped with n independently STR loci could be written byï¼ IBS~Bï¼2n, πï¼, and the general probability, π, could be given by the formulaï¼ [Formula see text].CONCLUSIONS:
In the biological full sibling identification, the probability of null hypothesis corresponding to any specific IBS score can be directly calculated by the general equations presented in this study, which is the basement of the evidence explanation.Key words
Full text:
1
Collection:
01-internacional
Database:
MEDLINE
Main subject:
Microsatellite Repeats
/
Siblings
/
Irritable Bowel Syndrome
Type of study:
Prognostic_studies
Limits:
Humans
Language:
En
/
Zh
Journal:
Fa Yi Xue Za Zhi
Journal subject:
JURISPRUDENCIA
Year:
2018
Document type:
Article
Affiliation country:
China
Publication country:
CHINA
/
CN
/
REPUBLIC OF CHINA