Best Method To Know The Biological Father Of Child

Father, mother and child

Paternity test is becoming very common. Paternity testing is a test done to ascertain the biological father of a child. Very rare cases a mother is involved. There are different types of tests available to test the paternity of a child.

Type Of Paternity Testing

Blood Group

In the first half of the twentieth century, the paternity of a child was done based on analysis of the blood group of a father and child. There are four types of blood groups in humans. That is the A, B, AB and O. A mother who has type B and a father with type O cannot give birth to a child with type AB. The father must have type A. But this method was dropped because of the possibility of having false exclusion and false inclusion.

Genotype

Honestly, this is straightforward. A man and woman cannot be  AA and give birth to a child that is SS. But this method does not hold much water because many people carry similar genotypes.

Blood Cell Antigen

In 1970, a new blood cell antigen or human leukocyte antigen (HLA) test was designed with 95 percent accuracy.

DNA Paternity Testing

This is by far the best and most reliable. It involves the use of deoxyribonucleic acid (DNA) sequencing. Every child is born with 50 percent DNA contribution from mother and father. The test looks for certain specific size pieces of genetic material of the father in the child that is identical. The test can be done using (blood) restriction fragment length polymorphism (RFLP) or buccal scrab. But both give the same result as DNA is the same anywhere.

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The sample is worked on. The DNA is extracted and amplified for analysis. The DNA diagnostic center recommends at least 20 short tandem repeat (STR) analyses. However, some laboratories use less or more. What that means is that the test looks at different locations in both the man and child DNA sequence and analyses up to 20 different location. Using few locations can result in false inclusion or false exclusion.

Paternity Test Before Birth

1. Noninvasive prenatal paternity test (NPPT): the fetal DNA found in the blood of pregnant women is analyzed with that of the man. It can be done from 7 weeks.

2. Chorionic villus sample (CVS): Small samples of the tissues from the placentae are collected through the cervix or abdomen. It can be done in 10 and 13 weeks of pregnancy. It carries some level of risk to the baby.

3. Amniocentesis: amniotic fluid is drawn through the abdomen and analysed. Can be done from 15 and 20 weeks of pregnancy. It also carried some level of risk.

Error In DNA Test

The DNA test is 90 to 99.9 percent accurate. However, due to error the result can either be false exclusion or false inclusion.

False Inclusion

False inclusion is when the test shows that a man is the paternal father when in reality, he is not. In a group of men, there will definitely be other men who will have some similar size pieces with a child. But the more the test is done, the more other men will fall off the sequence of location. This will continue until the real father is identified. So stopping testing at the first DNA location can give a false inclusion. To rule that a result is false inclusion, it is recommended that the probability should fall into 99.9 percent.

False Exclusion

This is common due to human error. Wrong sample result in false exclusion. Wrong samples could be as a result of poor samples supplied by the client or sample collection by the laboratory personnel. Also, testing the first location and result return negative should not be rule that the man is not the father. More locations of at least four need to be tested. This is because in some cases, the first one or two may not always match with the child just as even if the first one matches, the next may not match.

Home Test DNA Kit

Home test kits that we know are diagnostic testing devices that can be used at home and give results at home. However, all the DNA testing kits in the market today are not testing kits but the sample collection kits. The marketers have a laboratory where they analyze the result.

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When you buy a testing kit online, the sample is collected and labeled. The sample is sent to the laboratory for analysis. After some days, the result is sent back to the location.

Result Of DNA Paternity Testing

If a man IS considered the biological father, the report contains the following:

1. A conclusion statement that says that the alleged father is not excluded as the biological father of the tested child. This means he can’t be statistically ruled out and is considered to be the biological father of the child

2. A Combined Paternity Index (CPI), which is the odds that the man is the father of the child. For example, a CPI of 43,110,000 means there is a 43,110,000 to 1 chance that someone other than the man who was tested is the biological father instead

3. A Probability of Paternity, which is the chance—given as a percentage—that the man is the father. It’s generally 99.9% or higher, which would read: There is a 99.9% chance that this man is the biological father of the child.

If a man IS NOT considered the biological father, the report contains the following:

4. A conclusion statement that says the alleged father is excluded as the biological father of the tested child. This means he is not considered the biological father.

A Combined Paternity Index (CPI), which is the odds that the man is the father of the child. For an exclusion this number is always 0

5. A Probability of Paternity, which is the chance—given as a percentage—that the man is the father. For an exclusion, this number is always 0

DNA paternity test results can be out in about 2 to 5 days. The cost used to be about 200000 naira but is now 100000 naira in many laboratories. But adding any other person to it will add an extra cost of about 50000 naira only.