Step I random x-linked recessive question

[knuckles]

So I know hemophilia, like other XLR is almost never in females, unless they have a single X (turners), but what if the mother is a carrier and father is affected? That would mean 1/2 of the daughters would have the recessive allele on both X's. Would that cause hemophilia in the daughter, or would it cause a portal to open up to a parallel universe? Thanks.

 

[vr123]

i think it would but it would be extremely rare.

 

[knuckles]

come on, one of you geniuses must know.

There's gotta be carriers and affected men of XLR diseases that mate. Why are their daughters never mentioned as possibilities?

 

[hartbot]

vr is right

If a female has 2 x genes with a recessive mutation on it, of course it would manifest. But most of these diseases are so rare that we assume on tests and real life, that this is not the case...

Have you ever seen anyone with Hunter's disease?

 

[knuckles]

but hemophilia isn't that rare

 

[vr123]

but hemophilia isn't that rare

true, but the chance of all the steps that need to occur for a daughter to have hemophilia occuring together (female carrier has a child with affected male that happens to get both mutant alleles) is rare. you can try out the math if you wish.

 

[match2011]

It primarily affects males, but much less commonly excessive bleeding also occurs in heterozygous females, presumably as a result of extremely unfavorable lyonization (inactivation of the normal X chromosome in most of the cells).

Above is from Robbins Basic Pathology 8th edition.

From your question, hom females are definitely affected by this disease.

Hope it's helpful.

 

[knuckles]

It primarily affects males, but much less commonly excessive bleeding also occurs in heterozygous females, presumably as a result of extremely unfavorable lyonization (inactivation of the normal X chromosome in most of the cells).

Above is from Robbins Basic Pathology 8th edition.

From your question, hom females are definitely affected by this disease.

Hope it's helpful.

Thanks a lot.

true, but the chance of all the steps that need to occur for a daughter to have hemophilia occuring together (female carrier has a child with affected male that happens to get both mutant alleles) is rare. you can try out the math if you wish.

The math isn't that unfavorable. It's 1/2 of female daughters if a carrier mates with a disease carrying male. I don't see the problem.

 

[NotMeNow]

It primarily affects males, but much less commonly excessive bleeding also occurs in heterozygous females, presumably as a result of extremely unfavorable lyonization (inactivation of the normal X chromosome in most of the cells).

Above is from Robbins Basic Pathology 8th edition.

From your question, hom females are definitely affected by this disease.

Hope it's helpful.

Let's do the math guys...

1/5000 live male births have the disease. so p = 0.0002 and q = 0.9998

So for females the pr of disease = p^2, or 1 in 25 million.

So 1 in 25 million live female births will have hemophilia.

 

[knuckles]

Well when you put it that way, lol.

Are there any more common XLR diseases?

 

[match2011]

Let's do the math guys...

1/5000 live male births have the disease. so p = 0.0002 and q = 0.9998

So for females the pr of disease = p^2, or 1 in 25 million.

So 1 in 25 million live female births will have hemophilia.

you can not caculate like this way in clinic. Actually I saw one girl has hemophilia A before and the bleeding is more worse than boy. Can you believe it?