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.