Submitted by 29PiecesOfSilver t3_yqxoei in science
bigglyboblee t1_ivrycfl wrote
Reply to comment by socialphobic1 in In a first, doctors treat fatal genetic disease before birth by 29PiecesOfSilver
Many genes encode enzymes. A mutation in a gene may result in a defective enzyme (protein) product. Enzymes catalyze biochemical reactions , so not having a particular enzyme can have dire consequences physiologically. In enzyme replacement therapy, a functional version of the enzyme is given to the patient like a medication.
FedXFtw t1_ivs8fuh wrote
Do they also take enzyme blockers to block production of the defective enzyme?
SippyTurtle t1_ivs9092 wrote
Generally the defective enzymes don't do anything, and that's the problem. If they don't do what they're supposed to, you don't get the chemical reaction and thus don't get the end product you need. So to answer your question, no, enzyme blockers aren't needed.
TheXtraReal t1_ivspcir wrote
This. I cannot speak on the article directly ,I am not a doctor.
I have a rare medical syndrome. I produce an excessive amount of histimine (MCAS) but my body no longer produces the enzyme in the digestive tack, so I cannot process histimine. I'm under 40 in age.
This results in, almost all the time just me, being allergic to me. DAO help, for my specific aspect but it's not 100%, more like maybe 30-40%>.
Recap, outside of my over production. I cannot produce the enzyme to combat the over production, let allow normal levels. So when I eat, more often than not. I go into sezuires and anaphylaxis.
SippyTurtle t1_ivsr63k wrote
That's awful. I've had one patient with it as well so I'm a bit familiar with the condition. My understanding is that it's not so much overproduction as much as it's the mast cells being super sensitive to everything. Are there certain foods you're able to tolerate or do you have to survive on specific nutrition supplements?
TheXtraReal t1_ivtrlwg wrote
I am reactive to food. I'm still on my journey to learn and document but that's an exhausting task.
I also react to smells, like smoke and various other environmental aspects.
I don't eat much, say in an episode state. I've dropped 30lbs since March '22.
Another fun bit is it was confirmed I also had a rare water allergy. I found a high pH water I can consume but is hard to stay hydrated.
I don't react to orange juice, soooo yummy!
[deleted] t1_ivuw4of wrote
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EriAnnB t1_ivspypv wrote
Jeeezus, that sounds like a tough way to live.
TheXtraReal t1_ivtrp74 wrote
It is, it's ruined my life.
madcaplarks t1_ivsqekc wrote
Well this is reddits chance to turn this person's problems into the start of an elaborate Four Yorkshireman sketch!
Oooh luxury, when I eat, my stomach comes completely out of my backside and I have to use sharp implements to jab it back in again.
Sharp implements?! Oooh that'd be lovely, I have to have Charles Dance step on my fingers using boots covered in dog poo, then use my crippled pooey splintered fingers to rub gravel out of my eye balls.
Eye balls?! We DREAMED of having eye balls
Majin_Bae t1_ivs9cif wrote
No one’s answered your question and I have a biology degree and work for DoorDash so I can explain. Basically enzymes and what they bind to (substrate) can be summed up with the lock and key model. Depending on what the enzyme catalyzes, enough substrate that correctly binds to the enzyme will basically take up all the locks so the left over faulty keys won’t enter. although everything should be taken case by case, we know that enzymes have a high affinity for substrates that they’re after. So if there are enough correct enzymes available, they will bind to the substrates more readily out competing the mutated enzymes, like a key that goes into a lock smoother.
In the case these mutated enzymes out compete the normal ones, then youd be right about worrying about what to do with the bad eggs.
Hope this helps.
Killer7481 t1_ivsg30o wrote
> No one’s answered your question and I have a biology degree and work for DoorDash so I can explain.
real sadboi hours
[deleted] t1_ivsmjpz wrote
I know a particle physicist that works in a supermarket. Specialise too much, and there's no jobs if you aren't top of your field.
DootDootWootWoot t1_ivt2l1j wrote
Maybe he just prefers that life? ¯_(ツ)_/¯
I've found many specialists can often generalize if their livelihood depended on it.
EvadingBan42 t1_ivsl332 wrote
Is that like office hours?
FedXFtw t1_ivs9vct wrote
Are there any real world cases, be it disorders or syndromes, or just a disease or illness, which cause faulty enzymes which are similar enough, or reactive enough, where their mere existence is harmful to your health? In which case you'd need to both block the production of these AND provide the body with the proper ones
[deleted] t1_ivsbvbe wrote
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Zouden t1_ivu5mjs wrote
But that's a recessive disorder, meaning the presence of some mutated protein isn't sufficient to cause disease. I believe /u/FedXFtw is asking about diseases where even some faulty protein is sufficient to cause disease even if healthy proteins are present.
For that I would look at dominant disorders, like those involving structural proteins such as collagen. In Ehlers-Danlos syndrome, a mutation in one copy of a collagen gene is sufficient to weaken the collagen structures.
[deleted] t1_iwb7df8 wrote
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Zouden t1_iwb8s6j wrote
All genes are inherited the same way.
The difference between a recessive or dominant disorder is down to the actual function of the protein encoded by the gene in question; this in turn determines whether a loss of one copy of a gene (remember we have two of each) is sufficient to cause a problem. In many cases, losing function of one gene isn't a big deal because we have the other as a backup. Only when you lose two does disease occur. We call that recessive.
With dominant mutations, losing one is enough to be problematic. This is common in genes that encode for structural proteins, where you need every bit to work correctly.
An interesting case is the sickle-cell mutation of the hemoglobin gene. One copy of the mutation confers resistance to malaria, but two copies causes sickle-cell anaemia. The malaria resistance is a dominant trait, while sickle-cell anaemia is recessive.
rimjobnemesis t1_ivu0ek5 wrote
Thus the PKU test on newborns.
hypergol t1_ivsegyu wrote
sure, there are plenty of diseases caused by gain of function (rather than loss of function) mutations. Parkinson’s disease is one: loss of the ASYN gene is pretty much fine, but mutations in the gene cause familial (early onset) Parkinson’s.
[deleted] t1_ivshslo wrote
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DJ_Velveteen t1_ivspoqr wrote
Huntington's, I reckon. Although iirc Huntingtin (the defective protein that kills you) may not be an enzyme and I'm on a phone so it's not easy to check offhand
SerialStateLineXer t1_ivsivf0 wrote
Diseases caused by mutations resulting in toxic gain of function exist. Huntington's disease and some forms of ALS, for example. Generally these are inherited in a dominant fashion, since you only need one copy producing toxic proteins to mess things up.
For toxic gain of function mutations, there are various technologies for silencing the expression of toxic genes currently in clinical trials. Most of them use complementary RNA strands that bind to mRNA, preventing it from being used to synthesize proteins. I don't think any of these are currently FDA approved, but there should be some within a few years.
(Edit: According to Wikipedia, there are actually four RNAi (RNA interference) drugs on the market already).
Conversely, loss-of-function mutations are generally inherited in a recessive fashion, since one copy of a gene will usually produce enough of a protein. I believe that there are a handful of loss-of-function diseases inherited in dominant fashion due to haploinsufficiency (where one good copy cannot produce sufficient quantities of a needed protein).
There's some evidence that c9orf72 hexanucleotide repeat expansions, the most common genetic cause of ALS and FTD, involves both haploinsufficiency and toxic gain of function. Basically, the mutant c9orf72 protein doesn't fold correctly, producing toxic aggregations, and then there isn't enough good c9orf72 protein to clean up the mess. It's inherited in dominant fashion.
[deleted] t1_ivtbgix wrote
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OliQc007 t1_ivu8i53 wrote
How do the enzymes penetrate the cell ? Aren't they too big to ever get in, even through transporters ?
bigglyboblee t1_ivv3wre wrote
You are right that a limit of ERT is it’s penetration to particular tissues/cells.
However, transporters are not the only mechanism for cellular entry. Have you heard of receptor-mediated endocytosis?
You can check out this paper if you want to see the mechanism in more detail
[deleted] t1_ivv95yv wrote
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[deleted] t1_ivubudo wrote
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bigglyboblee t1_ivv2xio wrote
You can read the paper if you’re interested, from my skim she has to receive injections every couple weeks for the rest of her life.
I don’t see how a single dose would work for enzyme replacement therapy, but I am not an expert in this topic.
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