bio nerdiness
Ok this is a nerdy entry.. please feel free to skip it if you're so inclined. I've put most of it under lj cuts to make it easier for you to skip.
So, I was reading kaplan's mcat book about glycolysis, and there was one of those "clinical correlate"s (those are my favorite part of these books, btw.. cuz they apply the concepts to diseases and disorders and so on). It was about how deficiency in the final enzyme in the pathway can lead to hemolytic anemia, and goes on to give a general explanation on how that happens.
Ok I need to back up. Last night, after dinner, when we were sitting around drinking tea and eating little snacks, there happened to be a fava bean in one of the snack plates. So of course my brother siezed the opportunity to make fun of me and encourage me to eat it. (I have G6PD deficiency, or so I'm told.. and one of the things that would make me sick is fava beans) Anyway, so a mini-discussion on G6PD ensued, where my cousin asked how they knew I had the condition and my uncle answered hemolytic anemia.
I knew G6P stood for glucose 6-phosphate and I knew G6P was in the glycolytic pathway, but I never got around to looking up what G6PD was.. (I think I used to think it stood for G6P deficiency.. but I guess I didn't really think too much into it because that makes no logical sense, since G6P isn't an enzyme) so reading the clinical correlate and the mention of hemolytic anemia got me all excited (yes I'm a nerd), so I decided to look it up.
Among the most notable of my discoveries is that G6PD (G6P dehydrogenase) deficiency is an X linked recessive trait. So that means mom had to be a carrier and dad had to have it.. but as far as I know, my dad doesn't have any G6PD symptoms (though that's hard to tell because you don't get any symptoms until you're under oxidative stress.. They diagnosed me after I got sick as a baby and they gave me asprin and made it worse). I'm sure dad has taken aspirin and had fava beans and stuff though.. so I dunno, maybe they mis-diagnosed me? Or somehow I have some mutation that my parents didn't have? Another thing I thought of is that in females, one of the x chromosomes can be inactivated by methylation (genomic/parental imprinting).. so.. if this gene undergoes maternal imprinting, the x chromosome from the father would be inactive, even if it was normal.. and that could explain how dad doesn't have it and I do. haha wow my genetics book is becoming handier than I expected... I had to look up something earlier this year as well. I guess it's a good thing I did genetics after all..
I also found out how this deficiency leads to hemolytic anemia, but I'm thinking no one wants to know all those details.. :p Basically it involves the pentose phoshate pathway, one of the 3 metabolic pathways that occur in RBCs. G6PD produces NADPH, which works to keep glutathione reduced, which is responsible for removing peroxides. Too much peroxides weaken the cell wall and that causes hemolytic anemia because these weakened cells get taken up by the spleen and destroyed.
Oh another interesting thing is that G6PD deficiency is associated with resistance to malaria. In fact, anti-malarial drugs are actually harmful to people with G6PD deficiency.
So, I was reading kaplan's mcat book about glycolysis, and there was one of those "clinical correlate"s (those are my favorite part of these books, btw.. cuz they apply the concepts to diseases and disorders and so on). It was about how deficiency in the final enzyme in the pathway can lead to hemolytic anemia, and goes on to give a general explanation on how that happens.
Ok I need to back up. Last night, after dinner, when we were sitting around drinking tea and eating little snacks, there happened to be a fava bean in one of the snack plates. So of course my brother siezed the opportunity to make fun of me and encourage me to eat it. (I have G6PD deficiency, or so I'm told.. and one of the things that would make me sick is fava beans) Anyway, so a mini-discussion on G6PD ensued, where my cousin asked how they knew I had the condition and my uncle answered hemolytic anemia.
I knew G6P stood for glucose 6-phosphate and I knew G6P was in the glycolytic pathway, but I never got around to looking up what G6PD was.. (I think I used to think it stood for G6P deficiency.. but I guess I didn't really think too much into it because that makes no logical sense, since G6P isn't an enzyme) so reading the clinical correlate and the mention of hemolytic anemia got me all excited (yes I'm a nerd), so I decided to look it up.
Among the most notable of my discoveries is that G6PD (G6P dehydrogenase) deficiency is an X linked recessive trait. So that means mom had to be a carrier and dad had to have it.. but as far as I know, my dad doesn't have any G6PD symptoms (though that's hard to tell because you don't get any symptoms until you're under oxidative stress.. They diagnosed me after I got sick as a baby and they gave me asprin and made it worse). I'm sure dad has taken aspirin and had fava beans and stuff though.. so I dunno, maybe they mis-diagnosed me? Or somehow I have some mutation that my parents didn't have? Another thing I thought of is that in females, one of the x chromosomes can be inactivated by methylation (genomic/parental imprinting).. so.. if this gene undergoes maternal imprinting, the x chromosome from the father would be inactive, even if it was normal.. and that could explain how dad doesn't have it and I do. haha wow my genetics book is becoming handier than I expected... I had to look up something earlier this year as well. I guess it's a good thing I did genetics after all..
I also found out how this deficiency leads to hemolytic anemia, but I'm thinking no one wants to know all those details.. :p Basically it involves the pentose phoshate pathway, one of the 3 metabolic pathways that occur in RBCs. G6PD produces NADPH, which works to keep glutathione reduced, which is responsible for removing peroxides. Too much peroxides weaken the cell wall and that causes hemolytic anemia because these weakened cells get taken up by the spleen and destroyed.
Oh another interesting thing is that G6PD deficiency is associated with resistance to malaria. In fact, anti-malarial drugs are actually harmful to people with G6PD deficiency.