Genetic risk

[topher2018]

Is there a test that can be done to determine if I passed on any genetic predisposition for PA to my daughter?

[Gambit62 Administrator]

Unfortunately the genetics of B12 are quite complex and I don't think any genes that have a specific propensity to PA have been identified (similar situation with Hashi's) - clear that it does run in families but not clear what the interaction of genes and environmental factors is - there seem to be a huge number of variables involved.

[topher2018 in reply to Gambit62]

Thanks Gambit. It looks like it is a 25% chance of passing on the gene if the other parent doesn’t also have it based on some reading I have done.

[fbirder in reply to topher2018]

That only applies if it is controlled by a single gene. If it were then the patterns of inheritance would be much more obvious.

[Gambit62 Administrator in reply to topher2018]

genes can either be dominant or latent. Latent genes need other conditions before they are activated - which can be as simple as two copies of the gene being present (which would lead to 25% probability) but most of the time it is a lot more complex, eg there is a particular gene that can cause high cholesterol levels that actually requires low B12 levels for it to be activated, as well as copies of the gene. Most genes fall into this latent category - which is what makes predicting things so complicated. There is a genetic component to type 2 diabetes but the genes there require other external factors to be present before they actually kick in.