This is as obvious as the different sized noses on our faces.
primary topic for this lecture concerns differences in responses to 'pharamceuticals'.
These responses are often 'hidden', meaning they may never show up at all unless the
person is exposed to a particular drug.
mathematical work, Pythagorous noted that some people developed "favism" from
eating fava-beans or in some cases from exposure to the pollen. Favism results from
hemolytic anemia, in other words, the breakdown of red cells that occurs when an
oxidizing compound in the beans cannot be countered by reducing compounds present
in the cells of normal individuals. The consequences can be pain, hallucinations and
even death in extreme cases. We now know that favism is caused by a nearly non-
functional (0-7% of the normal catalytic ability) allele of a gene that codes for glucose-6-
phosphate dehydrogenase (G6PD), a gene that normally functions in red blood cells. It
produces NADPH which is required to reduce the oxidized form of glutathione that is
found after digesting fava beans. since the G6PD gene is on the X chromosome, the
problem is only seen in males.
causes favism. An allele that is translated into a protein with 8-20 % of the normal
activity found in most whites is fairly common in Africans, where the most common
allele is 88% as active as that in most whites. This was discovered when many soldiers
were given a shot of primaquineto prevent malaria. Some of the soldiers had a delayed
reaction with kidney pain, dark urine, and low RBC counts that led to anemia and
weakness. Fortunately in this case, where only the older RBCs break down, the soldiers
show rapid recovery. There is good evidence that as in the case of sickle cell anemia,
resistance to malaria gives certain G6PD alleles a selective advantage, even though they
can be harmful in other environments.
simplify the insertion of breathing tubes, etc. used for anesthesia. In most individuals, it
is broken down rapidly by the enzyme pseudocholine esterase, so that the muscular
paralysis is barely noticed if at all. However, about 1 in 2,500 individuals lack the
normal esterase. They havesuccinyl choline sensitivityand will die unless breathing is
maintained on an artificial respirator for the hour or so it takes to recover!
cases where resistant bacteria have evolved since the AIDs epidemic began) is
metabolized at very different rates. About half of the population are "slow metabolizers"
![[made with GoClick]](imgs/goclick.gif)