“Transgenerational genetics” primarily occurs when recessive genes are carried by parents but only manifest in their grandchildren after recombination, allowing traits to be passed directly to the next generation while skipping the parents’ generation.
Research has discovered that these four genes are more likely to be inherited from grandparents and passed on to grandchildren.
Genetic Disorders
The US Centers for Disease Control and Prevention has found that approximately 65% of children with genetic disorders have parents who do not carry the same genetic condition, but older family members do.
In other words, genetic disorders can be “inherited through the generations.”
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For instance, a 2-year-old child with physical abnormalities was diagnosed with a rare metabolic disorder. The child’s parents were concerned about the cause of the condition. Through genetic testing, it was discovered that the child’s grandparents were carriers of the disease-causing gene.
So, why do genetic disorders occur in this “skipped generation” pattern?
Experts suggest that while the disorder is “inherited through the generations,” certain recessive genetic disorders often require two copies of the faulty gene to cause the disease. In other words, if both grandparents and parents carry the recessive gene, there is a 1 in 4 chance that the child will inherit the disorder.
If the father carries the recessive gene and the mother does not, the child will not have the disorder. However, if both parents carry the recessive gene, the child is at a higher risk of developing the disorder.
Genetic disorders.
Height Growth Genes
It is not uncommon for both parents to be of shorter stature, even below 1m65, while their children turn out to be taller. In fact, this occurrence can be attributed to “inherited height from previous generations.”
It is likely that the older generation, in this case, the grandparents, are of taller stature.
Why isn’t height directly inherited by the children, but rather skipped to the grandchildren? This is because the diverse genetic makeup of the grandparents is not entirely passed on to their children. However, when the parents pass on their genes to their children, they contribute different growth-promoting genes, resulting in a significant increase in the child’s height.
Inheriting height from previous generations is not an uncommon phenomenon. In fact, according to a study by a UK university, about a quarter of taller children inherit this trait from their grandparents.
The study, published in Nature Genetics, suggests that height and body shape are influenced by multiple genes, and the combination of genes from grandparents can be recombined and expressed in grandchildren.
Height growth genes.
Red-Green Color Blindness Gene
Unlike other genes, the red-green color blindness gene is located only on the X chromosome, which makes its inheritance pattern more complex.
– If the father is color blind and the mother is normal, the son will be normal, while the daughter will be a carrier of the gene.
– If the father is color blind and the mother is a carrier, there is a 50% chance that the son will be normal/color blind, and the same odds for the daughter being a carrier/color blind.
– If the father is normal and the mother is a carrier, there is a 50% chance that the son will be normal/color blind, and the same odds for the daughter being normal/color blind.
– If the father is normal and the mother is color blind, the son will be color blind, and the daughter will be a carrier.
This inheritance pattern is known as “crossover inheritance.”
Single Eyelid Gene
Most people consider double eyelids to be more aesthetically pleasing, so when both parents have double eyelids, they often expect their children to inherit the same trait. While this is a common expectation, the reality may be disappointing.
According to “Human Genetics,” about 11% of couples with double eyelids will have children with single eyelids. Among these children, 83% inherit the single eyelid gene from their grandparents.
Why does this happen? This is because the double eyelid gene is dominant, while the single eyelid gene is recessive. If the grandparents carry the single eyelid gene, even if the parents have double eyelids, their children can still inherit the recessive gene from the grandparents and develop single eyelids.
Single eyelid gene.
This demonstrates that recessive genes can remain “hidden” for multiple generations before manifesting.
In summary, when parents notice that their children “don’t resemble them,” they shouldn’t be quick to jump to conclusions. Genetics is a complex and fascinating process where factors from multiple generations can unexpectedly come into play. Children may exhibit “skipped generation inheritance” and resemble their grandparents in certain aspects.
Furthermore, this highlights that each child is unique, carrying a special combination of genes from their parents and grandparents. Nature has its own way of creating diversity, and it is this diversity that makes us special.
Instead of focusing solely on genetic traits, embrace your child’s uniqueness, and accept that beauty comes from both the inside and out, along with their personality, talents, and the experiences they will have in life.
