It runs in the family

Olivia has this inherited condition called Alpha Thalassaemia minor. The thing about gene mutation and heritability is that it is not only restricted to one child (50% of the children of a couple would get it - think of 4 children, split 2-2, 2 have, 2 don't have), so that means that either my brother or I is a carrier of it, or we're both extremely lucky and my sister is the only one. But because I have no idea whether which of my parents is a carrier of it, or whether both are carriers (that'd be unlucky), I can't predict if one of us is a Alpha Thalassaemia major carrier. However, because both of us are alive and kicking, I don't think either of us has it.

If you're interested, the diagram would pretty much explain what I meant. This diagram illustrates the probability of a child inheriting the condition if only one parent has it:


This diagram illustrates the probability of inheriting the condition if both parents are carriers:


Unfortunately, this means we'd be going for a blood test next Saturday.