Is it true? about born handicap

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Discussion Overview

The discussion revolves around the genetic implications of incest, specifically the likelihood of having children with disabilities when parents are closely related, such as siblings. Participants explore the genetic mechanisms behind this phenomenon, including the role of recessive genes and the degree of relatedness.

Discussion Character

  • Exploratory
  • Technical explanation
  • Debate/contested

Main Points Raised

  • Some participants assert that the chances of having a child with a handicap are higher if the parents are closely related, but not as high as might be assumed.
  • It is noted that many genetic malfunctions do not manifest as disorders unless both copies of a gene carry the same mutation, which is more likely in closely related individuals.
  • One participant explains that serious genetic disorders are often recessive, meaning both parents must carry the same mutation for it to affect their child.
  • Another participant discusses specific examples of genetic disorders, such as Down syndrome and hemophilia, highlighting that not all disorders are recessive and that some, like Down syndrome, are due to chromosomal abnormalities.
  • There is a discussion about the varying risks associated with different degrees of relatedness, with direct relatives having a significantly higher risk compared to more distantly related individuals.
  • A participant raises a question about how far removed relatives can be before the risk of genetic disorders becomes negligible, suggesting that even distant ancestry could potentially link individuals.

Areas of Agreement / Disagreement

Participants generally agree that the risk of genetic disorders increases with closer familial relationships, but there is no consensus on the exact probabilities or the implications of distant ancestry.

Contextual Notes

Participants mention various genetic disorders and the complexities of inheritance patterns, but there are unresolved questions regarding the exact probabilities and definitions of "handicap." Additionally, the discussion includes some informal terminology that may not align with current medical standards.

Chitose
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Hello, Chitose wonder chick again.


It's about incest.
I don't care about it's illegal or not, I just want to know if it's true or not?

That if people have kid within own family, chance of that kid become handicap are very high
(Like blood relate brother and sister haveing a kid)

IS that really true?
If it's true, Why? a chromosome thing?

.........
I ask because there's some case happan to people I know is most likely these. They are real brother and sister but sister have sterile, so they marry to themself and prepared to abdopted child as their son.


And... Don't take this seriously, People that believe in Adam and Eve, which mean they believe in incest is common thing for human too?

.........
PS. English is not my native language, Please forgive If I'm worng in gramma or spelling.
 
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Chances of handicap are not very high, but a lot higher than if parents are not related.

Many people have malfunctions of some sort in their genetic code. These malfunctions do not show up as disorders, because most genes come in two copies (one from the father and one from the mother) and you need exactly the same malfunction in both copies of the gene to result in the disorder.

If parents are not related, it's very unlikely that they'll have the same mutation. If they are brother and sister, there's a good chance that they've inherited the same mutation from one of their parents. If that's the case, there's a chance that their children will have two bad copies of the gene.

Does that make sense?
 
Typically, really serious "malfunctions", like mongoloidism (apologies to all our Mongolian friends for that term!) or hemophilia, are recessive genes- that's because if a serious malfunction were dominant, people carrying that gene would all die out and the gene would disappear from the gene pool. Closely related people are much more likely to be carrying the same genes, so the same recessive genes, so the same "bad" genes.

"In breeding" is why the ruling families of Europe had such a high percentage of hemophiliacs- not to mention the famous "Hapsburg Lip" (which was actually a very pronounce "prognathis" (buck teeth)).
 
hamster143 said:
Chances of handicap are not very high, but a lot higher than if parents are not related.
It entirely depends on the degree of relatedness. If the persons are directly related (parent/offspring or siblings) the chances of a handicap are high, they should not be having children. The odds are much lower and acceptable for niece/nephew couples.

Many people have malfunctions of some sort in their genetic code. These malfunctions do not show up as disorders, because most genes come in two copies (one from the father and one from the mother) and you need exactly the same malfunction in both copies of the gene to result in the disorder.
That's true in the case of a recessive mutations.

HallsofIvy said:
Typically, really serious "malfunctions", like mongoloidism (apologies to all our Mongolian friends for that term!)
The PC-term is Down syndrome. It is a trisomy of chromosome 21, so it is not correct to say that it is a recessive gene.
 
It entirely depends on the degree of relatedness. If the persons are directly related (parent/offspring or siblings) the chances of a handicap are high, they should not be having children.

Assuming brother/sister incest: for any given recessive mutation, chances of a handicap are equal to the chance that one of the common parents has the recessive gene (for example, for phenylketonuria that's 1 in 25), times the chance that both the brother and sister get the bad gene (1 in 4), times the chance that their child gets two bad genes (1 in 4), so, for phenylketonuria the odds are 1 in 400, which is fairly low, but much higher than odds of the same disorder for the child of two unrelated people (1 in 10,000).

Hemophilia is not a very good example, because it's a X chromosome recessive disorder and things work out differently in that case.
 
I see... so, even normal people have bad gene inside but it's not show effect because it's not in pair right? people for same family share same blood and most likely same bad gene, if they have a kid, bingo their kid will recive bad gene in pair and become handicap.

but... how far blood line is safe?

you know, even two people from different place and parant, they great great great great grandfather migh in same family. the world is big anything like can be happen.
 

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