If both parents have blue eyes, can their child have brown eyes?
The answer to this question is more complicated than it would seem to anyone who remembers what was said in biology class at school. We used to present the problem in a simplified way, suggesting that eye color is determined by one gene and that the blue version of the gene is recessive. In such a "school" arrangement, if both parents had blue irises, they would have no chance of having a child with a different eye color.
Real eye color inheritance
In fact, eye color is determined by the amount of melanin (black pigment) and the ratio of eumelanin (dark brown pigment) to pheomelanin (reddish pigment). The OCA2 and HERC2 genes play the most important role in determining the color of the irises, but apart from those mentioned, there are at least 10 other genes known to influence this trait. Ultimately, the interaction of all these genes determines the final effect. Thus, blue-eyed parents can have brown-eyed children.
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 advice]Multiple Sclerosis Inheritance [Expert Advice]Phenylketonuria - does the course of 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]