Porphyria Educational Services
PORPHYRIA EDUCATIONAL SERVICES BULLETIN Vol. 1 No. 19 May 9, 1999
Focus: GENETIC TESTING
A generic disorder is a disease, disability or physical deformity
caused by some deviate gene formation. Any of the inherited types
of porphyria are that, a deviate gene formation.
It may be the absence of a gene or part of the gene. Sometimes it
is a mislocation of gene substance. And in some instances only
one gene -- or part of one gene-- can cause the disorder. At
other times it may have to be two or more genes which must be
affected before a disorder becomes obvious.
In porphyria is all takes place in the heme pathway. In the heme
synthesis.
Genes are composed of a long helix, as some have related it liken
to two spiral staircases intertwined of deoxyribonucleic acid
segments which we all know by the letters DNA.
It is the various combinations of these DNA units that impart
function as well as heritary characteristics to the cells that
make up boday organs, tissues and even appearance.
It is believed that damage to DNA following excessive exposure to
chemicals, drugs and ionizing radiation playsa critcal role in
inherited genetic disorders such as porphyria.
DNA is also, in essencem the infecting mayterial of bacteria and
viruses, They insewrt their DNA into the body's cells and then
reproduce themselves,causing disease.
AT present it is estimated that there are 15 million people in
the United STates alone, suffering from some form of genetic
disorder.
Because of this, it should be obvious, especially is there is
knowledge -- or even the vaguest hint-- of a genetic-type
illiness in the family tree.
It has been predicted that within a couple of years routine gene
mapping will be commonplace, and that all laboratories will be
eventually able to help determine an individual's susceptability
to a great many inherited diseases.
The testing for a DNA marker for a specific disease is also
entering the diagnostic field, and is available for porphyrics
through Mt. Sinai Hospital in Manhattan, New York under the
direction of Dr. Robert J. Desnick. At present only specific
types of porphyria are being tested.
This is a form of gene probing that constitutes predictive
testing for hereditary disease.
Genetic disorder screening has also been used as well to provide
information to indirectly related parties such as insurance
companies,health departments and motor vehicle bureas. The
availability of such data brings up the matter of
confidentiality. There is always the risk of such information
reaching the wrong hands and causing almost as much disruption of
one's life as the disease itself. So, those who submit to such
testing must be assured of the privacy of the results.
At the present time there ar well over 6,000 different inherited
diseases or traits that are known [exhibited by the carriers of
genetic diseases who do not usually show signs of the disease] .
The porphyrias reveal themselves as metabolic defects that
interfere with normal body enzyme chemistry. They can also be the
consequence of the lack of one or more enzymes.
Genetic screening tests try to uncover individuals who have a
greater-than-average-risk of passing on an inherited condition.