Having a child after infertility treatment, DNA test shows 'not biological father'

After many years of researching DNA and genetic testing in Vietnam, forensic expert Colonel Ha Quoc Khanh, former Deputy Director of the Institute of Criminal Science, currently a professional consultant at a genetic testing company in Thuy Khue (Hanoi), said he had encountered many rare cases and many surprising stories. But the case of a man in Ha Giang about half a year ago was the most complicated.

"The husband is the boy's biological father, but their DNA is not the same. This is a rare case, the first to be discovered through DNA analysis to determine blood relationships in Vietnam," said Mr. Khanh.

Mr. Viet Hung, 35 years old, from Ha Giang, Muong ethnic group, married Ms. Nguyen Thi Hoa, 30 years old, ten years ago. They now have a 5-year-old son. The boy is the result of 5 years of infertility treatment for the couple. Although very happy to have a son after a long time of waiting, Mr. Hung still has doubts in his heart when he sees that the older his son gets, the less he looks like him. Many people also whisper, "Why doesn't the son look like his father?"

Mr. Hung then took hair samples from himself and his child to Hanoi for a DNA test. The results confirmed that the two were not father and daughter. After bringing the test results home, Mr. Hung flew into a rage and interrogated his wife day and night, despite Ms. Hoa's tears and vows of loyalty. Family life began to be difficult with Mr. Hung's curses and "kicking the bucket and hitting the basket".

Many people have had their blood relationships accurately determined after DNA tests. Photo for illustration purposes only: gentis.

Seeing his wife firmly denying any cheating, and reviewing the time they had been together and not seeing any strange behavior from his wife, Mr. Hung decided to go to Hanoi for another DNA test. This time, he brought samples to another DNA research center, including hair samples and oral mucosal cells from himself, his wife, and his son.

The initial analysis showed that the mother and child were related, but the father’s sample was contaminated and could not be analyzed or concluded. The experts re-examined all steps in the testing process but found no errors. They re-tested all samples.

The results were the same for both the mother and child, but the father's sample showed two different results on different samples, in different analyses. Even the same hair sample gave different results each time. The hair sample test result was the same as the previous analysis, meaning there was no father-child relationship; but the oral mucosal cell test could not reach a conclusion.

Faced with this strange result, the examiners studied documents, exchanged and discussed with each other and with many outside colleagues to find the result.They asked the family to provide samples again. This time the father's samples were blood and sperm. The samples were sent to two different genetic research centers (including the Institute of Criminal Science) for both sides to independently test and compare to come to a solid conclusion.

"Before the test, we suspected that Mr. Hung could be the product ofChimerism, a phenomenon that occurs when two fertilized eggs (ie two embryos), have different genetic structures, due to the two embryos accidentally combining into one in the early stages of pregnancy. Or this is the combination of a fertilized egg with a degenerated cell during the division process... After having the results, we have more basis to confirm that this case is indeed Chimerism", said Colonel Ha Quoc Khanh.

Illustration of the chimera process: A baby boy was born to a couple, but was the biological son of his uncle. This uncle was a twin fetus that was swallowed by his younger brother (the husband) while still in the mother's womb.

To put it simply, during pregnancy, Mr. Hung's mother could have two embryos at the same time. Normally, two children would be born, with different genetic structures. But by chance, these two zygotes combined into one in the early stages of pregnancy. Mr. Hung was born with two different genetic structures (that is, two different sets of genes) in the same body.

When Mr. Hung gave birth to a child, the child did not inherit Mr. Hung's genes. That is why when taking samples from different tissues on Mr. Hung's body and his son's body, the results were different, even though he and his son were determined to be related by bloodline (ie, have the same genes).

Colonel Khanh said that chimerism in humans is rare, it is only discovered randomly in a specific situation, and to determine chimerism is very difficult.

In the world, the phenomenon of Chimerism has been discovered and announced by scientists. Mrs. Karen Keegan, 52 years old, in Boston, USA, was discovered to have Chimerism when she and her three children were tested to see if they could donate kidneys to her for transplant. The results showed that two of the three children were not her biological children. After a series of tests were conducted... the experts concluded that she had Chimerism.

Another case that was discovered was that of Lydia Fairchild, 26, from Washington, who wrote a request for monthly child support for her children to the authorities. However, this request was not accepted because DNA testing showed that the children were not Lydia's. Everything was only cleared up after Lydia was identified as a case of chimerism.

According to ngoisao.net