Three Parent Families

Some people carry dodgy DNA sequences in their genome which can cause genetic abnormalities in their children. For couples wanting to have a child its now become technically possible to replace those sections with the DNA of another, third, person to create a healthy embryo. Any child borne would be made up of the DNA of three people

I genuinely don't know how I feel about this. My brain says logically that its just a technical fix for a technical problem. Instinctively though I don't like it. It 'feels' wrong and could have unintended social and biological consequences. Thoughts?

http://www.bbc.co.uk/news/health-23079276

Mitochondrial DNA is only ever inherited from the mother - it comes from the egg cell, ( the mitochondria of the sperm get left outside on fertilisation as they are in the tail ). This, therefore, does not in any way affect the inherited characteristics of the child, it will be a 100% mix of the parents as the mitochondrial DNA cannot be integrated into the cell nucleus. All this is doing is replacing that part of the cell that produces energy.

Mitochondrial DNA is only ever inherited from the mother - it comes from the egg cell, ( the mitochondria of the sperm get left outside on fertilisation as they are in the tail ). This, therefore, does not in any way affect the inherited characteristics of the child, it will be a 100% mix of the parents as the mitochondrial DNA cannot be integrated into the cell nucleus. All this is doing is replacing that part of the cell that produces energy.

Thanks, I didn't know that. Does it not open up Pandora's box though? Once you have breached the principle of changing an embryos DNA to order for one situation it becomes easier to agree to do it for something else. What can start as a process designed to avoid medical issues can end up as a process positively selecting genes for looks, physique, intelligence etc.

It really isn't quite like that, so there would be no unintended social or biological consequences. You are talking about using someone else's mitochondria. Mitochondria have their own DNA probably because they used to be free-living bacteria which were absorbed into our ancestors cells, and the deal worked quite well for both of the organisms at the time. The mitochondrial genome is tiny at just ~16500 bases long whereas the human one is ~3,200,000,000 bases long. So it is a tiny 'alteration' that can make a huge difference to people's lives because of the role mitochondria play in the body.

Also, mitochondrial DNA is inherited entirely differently to the rest of the genome. All of your mitochondria come from your mother because the egg cell is just so large compared to the sperm cell meaning there are many more mitochondria present. Also, it believed that any mitochondria from the sperm cell that enter the egg cell are labelled with a protein called unbiquitin and basically digested down.

My point is that not only is it the smallest alteration that can make a huge difference to people's lives, such is the role mitochondria play, but also the inheritance of the mtDNA is entirely separate to that of the rest of the genome so you affect nothing to do with normal DNA.

Thanks, I didn't know that. Does it not open up Pandora's box though? Once you have breached the principle of changing an embryos DNA to order for one situation it becomes easier to agree to do it for something else. What can start as a process designed to avoid medical issues can end up as a process positively selecting genes for looks, physique, intelligence etc.

If they start meddling with the parental DNA then yes, selective breeding becomes an option.

It really isn't quite like that, so there would be no unintended social or biological consequences. You are talking about using someone else's mitochondria. Mitochondria have their own DNA probably because they used to be free-living bacteria which were absorbed into our ancestors cells, and the deal worked quite well for both of the organisms at the time. The mitochondrial genome is tiny at just ~16500 bases long whereas the human one is ~3,200,000,000 bases long. So it is a tiny 'alteration' that can make a huge difference to people's lives because of the role mitochondria play in the body.

 

Also, mitochondrial DNA is inherited entirely differently to the rest of the genome. All of your mitochondria come from your mother because the egg cell is just so large compared to the sperm cell meaning there are many more mitochondria present. Also, it believed that any mitochondria from the sperm cell that enter the egg cell are labelled with a protein called unbiquitin and basically digested down.

 

My point is that not only is it the smallest alteration that can make a huge difference to people's lives, such is the role mitochondria play, but also the inheritance of the mtDNA is entirely separate to that of the rest of the genome so you affect nothing to do with normal DNA.

Andy,

How do you know this?

Not meaning to be a rsey, genuinely interested to hear if you work/study in a related field.

Andy,

 

How do you know this?

 

Not meaning to be a rsey, genuinely interested to hear if you work/study in a related field.

I'm currently at uni doing a degree which involves studying a reasonable amount of genetics.

I'm currently at uni doing a degree which involves studying a reasonable amount of genetics.

But I do think you missed the subtext to the question. Sure maybe this particular mitochondrial DNA technique doesn't have wider implications - but the fact of allowing manipulation of embryonic DNA to achieve a different kind of baby does.

But I do think you missed the subtext to the question. Sure maybe this particular mitochondrial DNA technique doesn't have wider implications - but the fact of allowing manipulation of embryonic DNA to achieve a different kind of baby does.

It's not really a different kind of baby though in that sense. It's not like they will have blue eyes or something. It is literally the difference between a dead baby/severely disabled baby and a baby that can live a long and healthy life. The only thing that will change is that that child will be able to have the equipment to produce the right amount of energy to survive.

Some people carry dodgy DNA sequences in their genome which can cause genetic abnormalities in their children. For couples wanting to have a child its now become technically possible to replace those sections with the DNA of another, third, person to create a healthy embryo. Any child borne would be made up of the DNA of three people

 

I genuinely don't know how I feel about this. My brain says logically that its just a technical fix for a technical problem. Instinctively though I don't like it. It 'feels' wrong and could have unintended social and biological consequences. Thoughts?

 

http://www.bbc.co.uk/news/health-23079276

Pandoras box is already open I'd suggest.

Sent from my GT-P3110 using Tapatalk 2

But I do think you missed the subtext to the question. Sure maybe this particular mitochondrial DNA technique doesn't have wider implications - but the fact of allowing manipulation of embryonic DNA to achieve a different kind of baby does.

Now this is where it gets interesting - rather than, for instance, selecting blue eyes, what if both of the parents were carriers for Cystic Fibrosis, and by gene splicing chromosome 7 you could ensure the removal of the faulty gene for the CTFR protein, replacing it with a fully functional one ? This would prevent the disease from manifesting itself.

Shouldn't this be in the Pompey thread?

Now this is where it gets interesting - rather than, for instance, selecting blue eyes, what if both of the parents were carriers for Cystic Fibrosis, and by gene splicing chromosome 7 you could ensure the removal of the faulty gene for the CTFR protein, replacing it with a fully functional one ? This would prevent the disease from manifesting itself.

What proportion of genetic diseases do you think we could 'select out' and make extinct and what proportion are due to spontaneous mutation / poor copying etc?

I tried to make a baby with two other people once...

What proportion of genetic diseases do you think we could 'select out' and make extinct and what proportion are due to spontaneous mutation / poor copying etc?

I'd imagine that in the near future we will be able to screen and as you say 'select out' for diseases like Cystic Fybrosis which are basically down to one gene. However, not all genetic diseases are as simple as one gene and not all would come down purely to genetics either I'd imagine with environmental influences coming into play as well. I'd never be in support of what people call 'designer babies', but where it is a case of preventing death or disability I don't have any objections to some alterations.

As for your original question, I have no idea of the proportion of genetic diseases which would be easiest to tackle but this list might be useful.

http://en.wikipedia.org/wiki/List_of_genetic_disorders

All the ones which are just point mutations within one gene are probably the easiest to tackle. Edit: All genetic diseases (and indeed useful genes) effectively come down to mutations at some point though.

I tried to make a baby with two other people once...

You should include a female next time

We can but hope for cures.

Shouldn't this be in the Pompey thread?

i lold

THOUGHT this was about the ones from Portsea Island

You should include a female next time

They keep running away!

Thanks, I didn't know that. Does it not open up Pandora's box though? Once you have breached the principle of changing an embryos DNA to order for one situation it becomes easier to agree to do it for something else. What can start as a process designed to avoid medical issues can end up as a process positively selecting genes for looks, physique, intelligence etc.

I'd think of it as evolution of the species. As we develop the technical knowledge to do so, we will inevitably start to use these techniques regardless of political sentiment.

I fully support genetics and stem cell research. The faster we can defeat MS Parkinson's Cystic Fibrosis and dementia, the better.

There is already an imbalance and natural selection. The rich intelligent and beautiful already self select towards a designer baby.

It doesn't really worry me!