ABO Blood Testing
Including Parentage, Mutations, and Disorders
This page was last updated on Monday, November 04, 2013
ABO blood testing cannot prove paternity but in certain cases it can prove that a man is not the father of a child. For an example, a man having type AB blood cannot be the biological parent of a child with type O blood and conversely, this is also true for women. According to the American Association of Blood Banks the false paternity percentages of those tested are 27.9% (domestic) and 30.5% (foreign). These numbers may change from year to year due to statistical sample size and other factors. While some stores sell ‘home’ DNA testing kits, a private person cannot use the results as evidence in court. An accredited testing laboratory must do the testing and preserve the chain of custody. So these kits are a waste of money.
Please remember that statistics about false allegations of paternity can be misleading especially on daytime television where DNA paternity testing has replaced the soap operas. This is television at it is worse when it portrays false images of women crying backstage while these shows depict men as louts that cannot hold still. So when the announcer proclaims ‘you are not the father’ he jumps for joy while the weeping woman gets the attention. Nevertheless, when the roles are reversed, she prances and dances like a bully who made her score. It is just plain buffoonery.
Motherless DNA testing is often used to prove paternity (the father of a child). The problem is that this kind of testing can produce a false positive result. This occurs because the mother and any man can have identical markers at the same locus (location) in the DNA molecule. So motherless DNA testing can falsely include an the wrong man because it excludes half the evidence. This includes the possibility of detecting a chimera (a person with multiple sets of DNA and more than one blood type). The important fact to remember is that testing does not include all children because no reason exists to test all of them. So what we do know is that women, who do lie about paternity, are more likely to lie about paternity in successive pregnancies and births. This statistic does not include pregnancies that have ended by miscarriage or nullified by elective abortion. The point is that these statistics do not show the true rate of paternity fraud or adultery. They only show the rate of fraud or adultery in a subpopulation of tested persons.
Several organizations have reported that one in every three men tested for paternity is not the father. That is different from saying that men have been mislead one out of three times. Suppose no one has tested the biological father, then that number would be indefinite. In the past, before DNA testing, the mother's husband was the father (by law) of her child. Moreover, any unmarried woman who bore a child had to name the father or the child before she would receive child support benefits. This lead to many abuses because anyone could check the vital statistics, tax rolls, and other public data to select the man of her choice. If he were married, he was more desirable because she (the claimant) could also get money from his wife.
From the AABB
The Association of Blood Banks (ABB.) claims that it has seen the exclusion rate misused by several organizations who claim that women have misled men into believing they are biological fathers of children. Then the AABB added the following qualifier, ‘when the mother knows this not to be true’. That claim may be incorrect because a woman may say that one of several other men could be the father. Her claim would be that she was sexually active with these men and that too might not be true. Anyone can extract recently deposited sperm from a woman and place that sperm into another woman using the ‘Baster method’.
DNA testing is equivalent to a sieve that excludes all the other coins (in this example) so that only the quarters remain. However, the particular quarter that we are trying to find was minted in 1935 and a President used it to buy a pack of Black Jack gum. It decided the outcome of a kickoff of the 1947 Army/Navy game. A sailor used it to buy a gift for his daughter, who loved to play softball and grew to be a meteorologist. Now, many years later, it is in a dish on top of your bureau, and that is the short story. So when the AABB added the following qualifier, ‘when the mother knows this not to be true’, it seemed to support the right of women to lie about paternity. This means that she is the deciding arbitrator of her own transgressions and that is inane.
This is the problem. Say that a woman claims that she has had sex with ten men and one of them is the father of her child. If testing reveals that none of the men is the father of her child, then she has falsely accused ten men of paternity. If this recurs nine more times until we have tested 100 men without a true result of paternity, then she falsely accused this entire group of men. This means that no one can calculate the rate because no laboratory has tested the biological father. So when he is found, the statistic becomes relevant but only after that has occurred.
The Paternity Scam
This is how the process worked. If the mother showed signs of pregnancy before she married and her future husband agreed to marry her, then he was the father of the child. If he refused, then he could be forced into marriage and the proof was based on the progress of the mother’s pregnancy. Physicians and witnesses could establish this. However, many often ignored that fact because any unmarried woman who bore a child had to name her child’s father before she would receive child support benefits. This lead to many abuses because all she had to do was to check the public records and select any man. If he were married, she might get even more money.
Now, according to the official explanation, the law presumes that every male is the father. The reason for this is that a woman would claim that she was sexually active with a man although he never had any relationship with her. So paternity testing simply excludes who is the biological father but on a larger scale. Some claim that men often allege that the mother had multiple sexual partners as a part of their defense but that is not entirely true. A bulb baster looks like a large eyedropper used to moisten meat during cooking. However, women can employ a bulb baster for other purposes. The baster method is the most common way of artificial insemination and it only requires repetition and not multiple sources of semen. Moreover, anyone can obtain the materials without a prescription.
In California, and in other States, a woman can abort her husband's child and conceive a child by another man. Since the State presumes that the husband is the father, it requires him to support the child. So any woman can name any man as the father of her child and he has to prove that he is not the father. At this point, the mother might claim abuse and then he has to pay the additional costs of testing and litigation.
The courts have ruled against men because the best interests of the child exceeded proof of non paternity. The fundamental doctrine of family law is that it is the father’s duty to support their children and the courts view attempts to avoid paying child support with suspicion. This is especially true if the father had previously claimed paternity. Before a court will enter an order for paternity testing, it may try to first determine that it is in the best interest of the child. This often leads to paternity fraud by the mother and the court.
Disputing Parentage Prior to the Advent of DNA Testing
Until the late 1980's, the only way that a man could dispute paternity was with proof of impossible contact (usually ignored by many courts), lack of fertility (sterility, vasectomy - also ignored), and ABO blood typing. Even when ABO blood typing excluded a man, some courts ignored the evidence and ascribed to paternity to him. The California Supreme Court in 1946 ruled the Charlie Chaplin was the father of a child despite proof of blood group incompatibility. Too many judges never cared for the facts.; One part of this essay will describe blood group testing and how it may be used to exclude parentage.; Keep in mind that this testing was designed to prevent physicians from transfusing patients with the wrong blood. It was not designed to identify a particular individual.
A cell is a very small unit of protoplasm.; It usually has a nucleus surrounded by cytoplasm that is enclosed by a plasma membrane.; Chromosomes are gene bearing threadlike structures existing in the cell nucleus. Genes are units of inheritance usually occurring at specific points on a chromosome. Except for sex cells, humans have 46 chromosomes in these nucleate cells. Some cells do not have a nucleus. One example is the erythrocyte or red blood cell. This cell is actually a circular disk with concave faces. This specialize cell contains hemoglobin that allows it to carry oxygen from the lungs to the tissues and carbon dioxide from the tissues to the lungs. Humans have 23 chromosomes in their sex cells. These sex cells are the ovum or egg of a female and the sperm of a male. A child inherits half of its chromosomes from the biological mother and the other half from the biological father making the total 46.
An allele is a pair of genes. Each person has a pair of alleles relating to blood factors, one that determines blood type and the other determines rhesus factor. One pair of genes determines blood type and the other pair of genes determines rhesus factor. Each person has a pair of ABO blood genes that laboratories can test for the A antigen and the B antigen. When neither antigen is present, that person has type O blood. When both antigens are present, that person has type AB blood. A person has type A blood when only the A antigen is detected and these individuals can have the AO or the AA genotype. Likewise, a person has type B blood when only the B antigen is detected and these individuals can have the BO or BB genotypes. ABO blood testing cannot identify the genotypes that determine these blood types.
|Gene||Gene||Genotype||Blood Type||Red Blood Cell Antigens||Serum Antibodies|
|O||O||OO||O||None||Anti-A and Anti-B|
|A||B||AB||AB||A and B||None|
ABO blood also includes testing for serum antibodies. This serves to confirm or dispute the antigen test. If the test results do not agree, the laboratory must resolve the discrepancy. Since reactions are strong, weaker than usual reactions indicate poor technique, faulty reagents, or incompetence. Some laboratories have poor standards and no quality control. It was not until 1990 that researchers determined that A and B were the co-dominant versions of the same gene and that O was its recessive version. Persons who have the A antigen on the surface of their red cells will not produce anti-A antibodies because that antibody would cause the destruction of their own blood. For that same reason, persons who have the B antigen will not produce anti-B antibodies. That explains why persons who have the A and B antigens will not produce anti-A or anti-B antibodies.
Each person has a pair Rhesus Factor blood genes that laboratories can test for the Rhesus antigen. When the test has not detected the antigen, that person's blood is typed Rh negative (Rh-). Otherwise, it is typed Rh positive (Rh+). The problem with blood testing is that it cannot distinguish between the (Rh+ / Rh-) and the (Rh+ / Rh+) genotypes.
|Rh-||Rh-||Rh- / Rh-||Rh-|
|Rh+||Rh-||Rh+ / Rh-||Rh+|
|Rh+||Rh+||Rh+ / Rh+||Rh+|
When a woman who has Rh negative blood and has been exposed in the past to Rh positive blood from a previous pregnancy or by some other means, she may have developed antibodies to the Rh factor and this can harm the unborn child. Physicians have procedures that address this condition and that is why it is very important that women with Rh negative blood see a physician at the first sign of pregnancy. These percentages vary slightly from source to source and are applicable to Western Europe and North America. Other regions may have a different distribution.
|Rh+||38 %||34 %||9 %||4 %|
|Rh-||6 %||6 %||2 %||1 %|
|Totals||44 %||40 %||11 %||5 %|
Putting it Together
Here is a simple method of determining the possible ABO genotypes of a child. Put the letters of the mother's genotype in the pink column headers in alphabetical order. Then put the letters of the father's genotype in the blue row headers in alphabetical order. Now, combine the letters in each row-column intersection in alphabetical order.
The same method applies to determining the possible rhesus genotypes of a child. I substituted the letter 'M' for the 'minus' symbol and the letter 'P' for the 'plus' symbol. Rh negative is always represented by 'MM' or '- -' but Rh positive can be represented by either 'MP' (- +) or 'PP' (++).
I used the most common blood types in the following table to show how blood typing can exclude paternity or maternity. The biological union of a person having type [AO+] blood with a person having type [OO+] blood can only have children with [OO-], [OO+], [AO-], and [AO+] blood types.
|M||MM (-)||MP (+)|
|P||MP (+)||PP (+)|
The biological union of a persons with type [A-] and [O-] respectively can only produce children with [O-] and [A-] blood types; or so it seems.
|M||MM (-)||MM (-)|
|M||MM (-)||MM (-)|
Now see the results when blood type [A-] is not represented by [AO-] but by [AA-] in the following table.
|M||MM (-)||MM (-)|
|M||MM (-)||MM (-)|
The biological union of a person having type [AA -] blood with a person having type [OO-] blood can only yield children with type [AO-] blood. But since blood testing cannot distinguish between type AO and type AA blood, the unfortunate male with type AA blood could be held as the father of a child with type O blood.
The following matrix shows the possible blood genotypes of a child (in the blue columns and rows) resulting from the genotypes of its biological parents. Use one row and one column for each parent's genotype shown in the grey titled boxes. The child's possible genotypes is at the intersection of the selected row and column.
|OO||OO||OO or AO||AO||OO or BO||BO||AO or BO|
|AO||OO or AO||OO, AO, or AA||AO or AA||OO, AO, BO, or AB||BO or AB||AO, BO, or AB|
|AA||AO||AO or AA||AA||AO or AB||AB||AA or AB|
|BO||OO or BO||OO, AO, BO, or AB||AO or AB||OO, BO, or BB||BO or BB||AO, BO, or AB|
|BB||BO||BO or AB||AB||BO or BB||BB||BB or AB|
|AB||AO or BO||AO, AA, BO, or AB||AA or AB||AO, BO, BB, or AB||BB or AB||AA, BB, or AB|
The following table shows how to determine the provisional father's blood type when the child's and the mother's blood type is known. Use the columns (green) for the child blood type and the rows (pink) for the mother's blood type. The intersection of the selected column and row gives the possible blood types of the provisional father. For an example, if a woman has blood type B and her child has blood B, the blood types of the possible father can be found by looking in the block in row B under column B.In this example, the provisional father can any male from the four possible blood groups.
|O||O, A, or B||A or AB||B or AB||Not possible*|
|A||O, A, or B||O, A, B, or AB||B or AB||B or AB|
|B||O, A, or B||A or AB||O, A, B, or AB||A or AB|
|AB||Not possible*||O, A, B, or AB||O, A, B, or AB||A, B, or AB|
|* Retesting is required.|
Through the years, those who read my work have asked me about their having a different blood type and rhesus factor from their parents. So, I have added two tables to my paper so that others can satisfy their curiosity and understand why ABO blood testing is not a good test of paternity.
The following tables are designed to show symmetry. The light-blue column headers denote the blood type of the father. The light red row header denotes the blood type of the mother. At the intersection of the row and column is a light-green rectangle that gives all of the blood types of their biological child. The same is true for the rhesus factor table but I chose, out of brevity, to use the letters ‘P’ for positive and ‘N’ for negative.
|O||O||A or O||B or O||A or B|
|A||A or O||A or O||A, B, AB, or O||A, B, or AB|
|B||B or O||A, B, AB, or O||B or O||A, B, or AB|
|AB||A or B||A, B, or AB||A, B, or AB||A, B, or AB|
|N||N||N or P|
|P||N or P||N or P|
A gene mutation is a permanent change in the DNA sequence that makes up a gene. They may affect a single DNA base or a large segment of a chromosome. They occur in two ways. They are either inherited from a parent or are acquired during an individual’s lifetime.
Germ cell mutations (those of egg and sperm cells) are present throughout a person’s lifetime and in nearly every cell of a person’s body. These types of mutations may exist in only one family member and that explains why there is not family history of the disorder. Conversely, acquired mutations are usually caused by changes in the environment. However, they may randomly occur during DNA replication. Since they are random, they are considered hereditary or passed from the parent to the child.
Mutations also occur in a cell within an embryo. So as the cells divide and multiply during development, an individual can have some cells with a mutation and some cells without the mutation. This forms a mosaic of DNA where the organism or parts of it are made up of cells two or more genotypes. This condition is called mosaicism or chimerism.
According to the literature, some genetic changes are very rare while others may be very common in a selected population. So if more than 1 percent of the population has a specific genetic change, those types of changes are called polymorphisms. These changes are often common enough to be a normal variation in the DNA and are responsible for many common differences between people such as blood type, eye color, and hair color. While most changes have little effect, others may affect a person’s health.
A chimera is a person whose DNA came from their sibling(s) in utero (in the uterus and before birth). This means that some people have multiple sets of DNA and more than one blood type. In the ABO system all blood is included in four major groups. However, there are more than two hundred minor blood groups and this can cause problems if a suitable supply of blood is not available. So some things are not as straight forward as they seem.
A chimera may develop from monozygotic or dizygotic fetuses. If the fetuses are a result of a monozygotic union, their DNA will be identical and if the fetuses are a result of a dizygotic union, their DNA will be different. This means that dizygotic individuals can be identified by chromosomal comparisons from various parts of their body. So some persons who are chimeras may have unusual physical features. For an example, one eye may brown while the other eye is blue. Some individuals may exhibit mosaic skin colorations. Others may have the biological characteristics of the male and female gender.
Sometimes chimerism is expressed as conjoined individuals. This occurs when a single zygote of monozygotic individuals fails to completely separate. According to the most recent literature (2010), this condition occurs in about one in 50,000 human pregnancies and most conjoined individuals are now evaluated for surgery to separate them. However, there is a dilemma, because an individual might have to be sacrificed to save the other.
Notes from the American Association of Blood Banks
The husband is tested to rebut the legal presumption that he is the biological father of the child. In each of these examples, there is no evidence that a large number of the men excluded in the testing were misled into believing they are the biological fathers of a given child. The information about false paternity percentages came from American Association of Blood Banks on March 9, 2006. As any reader should know, statistics can change from year to year.
Notes from the United Kingdom (The Guardian?) - In 2008, the Government of the United Kingdom had exposed more than 4,800 claims (4,854) of false paternity but there has not been a single prosecution for the crime.
Wikipedia on the ABO blood group system.
Wikipedia on the Hh_antigen_system (Bombay Phenotype).
Sickle Cell Anemia.
Mutations and disorders - please click here.
DNA testing and Chimeras - please click here.
For more information from the American Association of Blood Banks.
Annual Report Summary for Testing in 2006 - Prepared by the Relationship Testing Standards and Accreditation Program Units
How to Lie with Statistics - Darrell Huff, (1991) How to Lie with Statistics, Penguin; New Edition, ISBN 0140136290
The mention of any entity in this or other papers is for completeness and reference only. The laws in any state can change because that is what legislators do. So any quotation of the law is only what the law was when I read it.
Edward Steven Nunes
Monday, November 04, 2013 12:21:00 PM PST