Posted by Sidd from IP 66.171.246.115 on February 28, 2006 at 20:57:25:
In Reply to: please try this Q!!! posted by Nadia on February 28, 2006 at 15:21:34:
ANTICIPATION: Not likely, Nadia does not remember the disease as appearing succesively earlier in subsequent generations or being more severe (Which is is what anticipation is). Plus, as far as i know, Anticipation is seen only for triplet nucleotide disorders: Huntingtons, Myotonic dystrophy, Fragile X... whats the forth one... damn...
GENETIC HETEROGENEITY: refers to the many genotypes> same phenotype phenomenon. poor example, but if both the sickle cell mutation and spherocytosis mutation cause hemolytic anemia, i would call that phenomenon genetic heterogeneity. Two people with the same cliniccal s/s have different mutations.
INCOMPLETE PENETRANCE: refers to the same disease occuring in some patients of the family but not occuring in others. i dont think that fits in here.
MULTIFACTORIAL INHERITANCE: No way! This is multiple factors causing the same disease. Hypertension is the classic example. I think a good example of this would be: all family members are african american, some develop hypertension while some dont. Why?
VARIABLE EXPRESSIVITY: is, i think, the right answer. The same mutation causing different phenotypical manifestations. In this case, i think it must have been some very important tumor supressor gene that must have been lost: Rb? p53? one of them...
HOPE IM RIGHT!