Human Genetics and Medicine - BIOL 272    Homework for exam III - due April 22, 2010

Distinctive genetic traits and genetic disorders can arise through any of many mechanisms, and sometimes more than one process is involved in a genetic modification.  Among the more common and well-described categories of genetic alteration are
A.  lethal alleles
B.  multiple alleles
C.  epistasis
D.  incomplete penetrance
E.  variable expressivity
F.  pleiotropy
G.  a phenocopy
H.  genetic heterogeneity

Select five (5) of these processes.For each of the five you have selected, find a genetic disorder that exemplifies that mechanism of genetic change from the wild type. [Instructions in class were to select disorders not discussed in the textbook].

For each of these
    describe the disorder
        include why this is considered a disorder, not just a variation within the population
        when do the symptoms arise during development
        is there a cure or treatment?
    describe and explain the genetic process (or processes) that underlies the disorder
    consider, describe and explain, what tests or studies can be used to track the disorder
        can the problematic allele(s) be detected in potential parents?
        can the problematic genetics be detected before birth or before symptoms arise?
        can you imagine any preventative measures?
    what is possible now?
    what do you envision for the future?  explain
    discuss the ethical ramifications of intervention and detection

In some cases one or another of these element may be key, and deserving of elaboration, while for another disorder some other feature is the central issue.

Write these as short essays, not as a series of bulleted answers.  The list of points to address is intended as a guide, not as a set of short answer questions.