Porphyrias Sentence Examples
The porphyrias are disorders in which the body produces too much porphyrin and insufficient heme (an iron-containing nonprotein portion of the hemoglobin molecule).
This situation is the main characteristic of the porphyrias.
In general, the porphyrias primarily affect the skin and the nervous system.
Although there are eight steps in heme biosynthesis, there are only seven types of porphyrias; a defect in ALA synthase activity does not have a corresponding porphyria.
Although certain porphyrias are more common than others, their greater frequency is only relative to other types.
All porphyrias are considered to be rare disorders.
In the past, the porphyrias were divided into two general categories based on the location of the porphyrin production.
Porphyrias affecting heme biosynthesis in the liver were referred to as hepatic porphyrias.
Porphyrias that affect heme biosynthesis in immature red blood cells were referred to as erythropoietic porphyries.
As of 2001, porphyrias are usually grouped into acute and non-acute types.
AdvertisementAcute porphyrias produce severe attacks of pain and neurological effects.
As with all porphyrias, it is an uncommon ailment.
The underlying cause of all porphyrias is a defective enzyme important to the heme biosynthesis pathway.
For this reason, this group is often referred to as the acute porphyrias.
The erythropoietic porphyrias and porphyria cutanea tarda do not follow this pattern and are considered to be chronic conditions.
AdvertisementAs a final test, measuring specific enzymes and their activities may be done for some types of porphyrias; however, such tests are not done as a screening method.
In the future, scientists expect development of gene therapy for the remaining porphyrias.
A child who has been diagnosed with one of these porphyrias can prevent most attacks by avoiding precipitating factors, such as certain drugs that have been identified as triggers for acute porphyria attacks.
Gene therapy is a possible future treatment for these porphyrias.
As with other porphyrias, the first line of defense is avoidance of factors, especially alcohol, that could bring about symptoms.
AdvertisementFor the most part, the porphyrias are attributable to inherited genes; such inheritance cannot be prevented.
Prenatal testing for certain porphyrias is possible.