Module 2
Genetic Diseases
Prof Mary Waye
Discovery of genes involved in human diseases is on the verge of a major
revolution. Over the course of a mere 3 decades during the late 20th century, scientists
boosted DNA sequencing effort many orders of magnitude over by using automatic DNA
sequencers with capillary electrophoresis. While it cannot be said that every gene has
been sequenced and a human disease discovered with its defective counterpart; it is likely
that almost everyone will look into their genotype for a better understanding of their
disease predisposition within the next decade (1). Take the breast cancer gene BRACI,
for example. It is a very useful marker for woman who has a family history of breast
cancer and carries the susceptibility locus. Although only approximately 5% of the
breast cancer patients carries the mutant BRACI gene; for those affected, knowing
whether they have the gene is an invaluable piece of information.
In this new era of genetic engineering, genes are not only useful disease markers,
they are also important agents for gene therapy.
In this lecture, some aspects of the following genetic diseases will be discussed:
G6PD deficiency, Downs syndrome, osteoporosis imperfecta, Hungtingtons disease,
cystic fibrosis, and the CATCH22 syndrome. The molecular basis of the diseases as
well as other interesting related problems in the search for the culprit will be discussed.
References:
1. Ingelman-Sunberg, M.I., M. Oscarson, R.A. McLellan (1999) Polymorphic human
cytochrome P450 enzymes: an opportunity for individualized drug treatment. 1 :
Trends
Pharmacol
Sci
1999
Aug;20(8):342-9
(for
abstract,
see
http://www.ncbi.nlm.nih.gov:80/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_
uids=10431214&dopt=Abstract)
2. http://www.ncbi.nlm.nih.gov/omim/
Online Mendelian Inheritance in Man. This database is a catalog of human genes and
genetic disorders authored and edited by Dr. Victor A. McKusick and his colleagues
at Johns Hopkins