We have a problem with our husband. We are already a few years after the wedding. We got married as kids because I was pregnant. My husband knew perfectly well that I was not pregnant with him, but with another man. We met when I was already pregnant, but he decided to take on the baby. We had sex when I was in the first trimester of my pregnancy. When I gave birth, it was obvious that the baby looked nothing like any of us. The husband is blonde with blue eyes, and the father of the child is a brunet and I am also a brunet with dark eyes. And after these quite long years, I noticed how the child changed, that instead of being similar to me or my biological father, he became blond with blue eyes, even blue eyes. Is it possible that my son may have acquired some of my husband's genes?
A "ready set" of our genes is obtained at the time of fertilization of the egg by the sperm. We inherit the vast majority of genes by receiving one copy from the mother and the other from the father (with the exception of genes located in the mitochondria - cellular structures responsible for energy production that we inherit only from the mother, and genes responsible for male development located on the Y chromosomes, which men inherit only. from their fathers).
The amount of genetic material must be carefully balanced for the embryo to develop properly. During the development of an existing embryo, it is not possible to "mix" additional genes from, for example, another man's sperm. On the other hand, the fact that parents with dark eyes may have a child with light eyes is consistent with Mendel's laws (basic principles of classical genetics).
Simplifying - the gene that determines eye color comes in two variants - the feature of light (j) and dark (C) irises. The trait of having light irises is a recessive trait, i.e. in order for it to reveal itself, we must have both n copies of the gene - one is inherited from the father and the other from the mother.
The feature of having dark irises is dominant, i.e. even one copy of the C gene is enough to reveal itself. So dark eyes will have both CC (inheriting the gene variant that determines dark irises from both parents) and Cj people (inheriting such a gene variant only from one of the parents).
If partners Cj and Cj get together,this is because each of them will give the child one copy of the gene, so statistically 3/4 of their children will have dark eyes (BB, Bn, nB system) and 1/4 will have light eyes (nn system).
Remember that our expert's answer is informative and will not replace a visit to the doctor.
Krystyna SpodarKrystyna Spodar - specialist in the field of clinical genetics at NZOZ Genomed, ul. Ponczowa 12, 02-971 Warsaw, www.nzoz.genomed.pl, e-mail: [email protected]
The expert answers questions about genetic diseases and congenital malformations, inheritance, and prenatal diagnosis.
More advice from this expert
Bronchial Asthma - Likelihood of Inheritance [Expert Advice]Azoospermia - what genetic tests for a man and a woman? [Expert advice]Genetic testing before planning a baby - relationship with a cousin [Expert's advice]Prenal examination - transvaginal and abdominal ultrasound [Expert advice]Is alcoholism hereditary? [Expert advice]Is colon cancer hereditary? [Expert advice]Could a DNA paternity test be wrong? [Expert advice]Positive blood group in the parents and negative in the child - is it possible? [Expert advice]Two biological fathers. Is it possible? [Expert advice]Cancer gene inheritance: how to determine the likelihood of developing cancer? [Expert advice]Inheritance of tumors. Family predisposition to developing cancer [Expert's advice]Multiple Sclerosis Inheritance [Expert Advice]Phenylketonuria - does the disease depend on a gene mutation? [Expert advice]Phenylketonuria - what additional tests should I perform? [Expert advice]Phenylketonuria and Disability [Expert Advice]How to establish paternity on the basis of blood types? [Expert advice]What determines the color of the child's eyes? [Expert advice]Blisters on the feet and hands - is it a genetic defect? [Expert advice]Rh + (plus) parents and Rh- (minus) child. How is the RHD gene inherited? [Expert advice]Risk of chromosome 21 trisomy in the fetus [Expert advice]Persistent anal pruritus - a genetic disease? [Expert advice]Establishing paternity on the basis of blood type [Expert's advice]A child's genetic defects - tests [Expert's advice]Ulcerative colitis [Expert Advice] Children's he alth from a cousin relationship [Expert's advice]Rett syndrome - tests in the second pregnancy [Expert's advice]