If it is known that someone in a family has porphyria and their enzyme value is indicative of porphyria, other family members who have inherited this deficiency can be identified by measuring their enzyme levels. Latent cases so identified can avoid agents known to cause attacks. However, in some AIP families, PBGD is normal in red blood cells and is deficient only in the liver and other tissues. This is where the tricky area of a confirmed diagnosis is found in my family mutation of this inherited metabolic disease. Falsely low values sometimes occur due to problems with collecting and transporting the sample.
Timing is also most important in when tests are administered.
Tests should if at all possible be started at the very onset of an acute attack. And frustratingly, the tests often have to be repeated more than once. DNA is the material in cells that encodes all the genetic information of an individual. Almost every family with AIP has a different mutation in this gene. Within one family, however, everyone who inherits a deficiency of PBGD has the same mutation.