DNA Analysis (Parentage, Paternal, Immigration, Siblingship)

Calculating Probability of Paternity (PrP)
Formula; PrP (%) = (1/CPI -1) x 100
Example 1
DNA Probes            PI Value
A1 (15)                         A2 (25 )
A3 (22.5)                     A4 (60.3 )


Step 1. Multiply the PI Values, CPI;  CPI = 15 x 25 x 22.5 x 60.3 = 108,781
Step 2. Plug the CPI value to the equation of
                              PrP (%) = (1/CPI -1) x 100
                              Probability of Paternity (PrP) = (1/508,781) -100 = 99.999 %

The Combined Paternity Index (CPI), which is done on a pool base on race is derived from multiplying all of the PI's involved. The higher the value of CPI, the more likely the alleged father is the father of the child. CPI is rated on the following.
CPI Values                   Rating (likelihood of being the father)

20-99                                             Low
100-399                                          Moderate
> 400                                             Very High


Probe - a fragment from a labeled DNA used as a means of identifying certain locus DNA

Sample DNA analysis report

Dan D. Lion, a refugee from the island of Maldive was the subject of scrutiny for fathering the child of the famous orange orchid flower smeller, Sonia Sampaguita. Dan D. Lion denies the allegations that he ever touched this woman. He asked that his guilt be proven. He agreed to a DNA Paternity analysis.

The participating parties of Hispanic race for DNA Paternity testing include the child, the alleged father, and the mother.

Figure 1. DNA analysis result for the child, mother, and alleged father.
 DNA probes with corresponding
 PI
values
Allele Pair Size (kbp)  
DX1, PI 27.5 2.6, 1.29 2.6, 1.75 3.5, 2.1
DX2, PI 77.3 3.81, 2.86 4.56, 4.1 4.85, 4.1
DX3, PI 12.5 5.88, 4.23 4.95, 3.89 4.95, 3.1
DX 4, PI 33.5 2.25, 1.75 2.62, 2.15 3.79, 3.44

According to Figure 1, an allele size match occurs from the mother and child having allele size of 2.60 using DX1 probe, and the alleged father and child having allele size of 4.10 and 4.95 from DNA probes of DX2 and DX3, respectively.

To substantiate the allele size match findings, the following factors of CPI and PrP were calculated.

CPI = 27.5 x 77.3 x 12.5 x 33.5 = 890,157

Probability of Paternity (PrP) = (1/890,157 -1) x 100 = 99.999 %

In conclusion, the alleged father is 99.999 % probable and 890,157 times more likely to be the true biological father of the child as compared to a non-analyzed random male of equal race.


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