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Name: Karen
Status: Other
Age: 40s
Location: N/A
Country: N/A
Date: N/A 


Question:
What does it mean when a child born through incest has 1/4 recessive genes?



Replies:
Karen,

If both the parents have a recessive gene, the child will either have 2 (a full set for that characteristic), 1 (half set), or none of that gene.

I suspect that what you're trying to paraphrase is that the child born has a 1 in 4 chance of having both genes recessive. If both parents have one dominant (D) and one recessive (R) gene, each one will give either their D or R, independent of what the other parent gives. So the possible combos are:

Parent 1 Parent 2
D R
D D
R R
R D

In the DR, DD, and RD cases, there is at least one D, so 3 out of 4 cases the recessive trait will not show up, but in 2 out of 4 cases, the child will be a carrier (RD and DR). Only in one case out of 4, the child will have both genes recessive, and likely display whatever characteristic is contained in that gene.

Don Yee


The terminology is incorrect. Many of the paired genes in many cases are the same, but they may or may not be recessive. Incest children have high risk of diseases and conditions that may be harmful since the genes they are working with are not different enough to off-set these conditions. One receives one set of chromosomes from each parent and when the parents have similar genes, the recessive genes that are mutated or genes that represent bad qualities may be paired with the exact same gene, causing that trait to be evident. Yes, in most cases, these are recessive genes, but your question is asking about gene pairing. I suppose that about 25% of the genes would be the same. Well, that is excluding crossing over.

This was most evident with the royal lines where royalty married royalty and many were closely related.

Steve Sample


If the parents of a child are both carriers of a trait the child has a one-fourth chance of inheriting the trait. This is true whether the parents are related or not. The reason incest is bad is because traits tend to run in families. So if the partners are in the same family more of the family members will carry the trait and the more likely it is that the child could get it.

Van hoeck



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