Sunday, July 18, 2010

Defining: Acute Intermittent Porphyria (AIP)

Defining: Acute Intermittent Porphyria (AIP)
This is for “Joe, the Plummer” and Everyone Else

AIP is an autosomal dominant genetic (in-born) condition. (Gene Locus 11q23.3) provides a nice Power Point Demonstration on human genetics.

Genes are part of “the body’s basic instruction guide”. If a particular part of “the guide” is faulty or missing the job cannot be completed correctly.
My AIP stems from “a missense mutation, R116Q, in one of my HMB-sythase alleles.
My PBGD enzyme instructions are “mutated”/damaged.
In Acute Intermittent Porphyria only one parent needs to have an “abnormal instruction guide” and approximately 50% of the couple’s children will have the same condition.
I think of genetic alterations like a good cookie recipe that someone has either distorted by spilling coffee on… or it has been ripped and is missing some key information. What you get when you use “the recipe” is a “different cookie”…maybe too much sugar… not enough flour or no chocolate chips at all!!! Sometimes you hardly know that something is missing, while other times so much is missing from “the recipe” that it doesn’t turn out at all.

There is a porphobilinogen-deaminase (PBGD) enzyme deficiency.

An enzyme is an essential protein that assists in the body’s biochemical processes. In AIP there is a deficiency in the porphobilinogen-deaminase (PBGD) enzyme. PBGD is the third enzyme (ingredient) the body requires in the heme-making process.
I have been diagnosed with a 50% enzyme deficiency.

The body’s ability to effectively supply heme is altered.
This alteration can create shortages in times of need.

Heme is full of iron and makes red blood cells red. It can be found in all body tissues. Heme is most concentrated in blood, bone marrow and liver.
Heme is a component of hemoglobin, which is needed to transport oxygen from the lungs to all parts of the body, and then take the carbon dioxide from the body to the lungs to be exhaled /removed.

This information was modified from the Mayo Clinic information at

There is an abnormal accumulation/ build-up of bio-chemicals (porphyrin precursers & porphyrins) in the body (primarily: ALA- an amino acid & Porphobilinogen- a pyrrole).

Although porphyrin precursors (ALA & PBG) and porphyrins are normal body chemicals, it's not normal for them to accumulate in the body.

The Mayo Clinic has a good Porphyria explanation at

Abnormal bio-chemical concentrations in the body cause damage, altering the body’s ability to function properly.

Drugs (especially ones that require cytochtome P450 enzymes), fasting, dieting, smoking, illness, and stress, are some examples that increase the body’s demand for heme made in the liver. This “trigger” turns on the body’s ALA & PBG buttons… and large amounts of ALA & PBG are produced. These biochemical products accumulate because of AIP’s in-born enzyme deficiency.

I used the following article as a basis for the information contained in this summary.
Recommendations for the Diagnosis and Treatment of the Acute Porphyrias
Karl E. Anderson, MD; Joseph R. Bloomer, MD; Herbert L. Bonkovsky, MD; James P. Kushner, MD; Claus A. Pierach, MD;
Neville R. Pimstone, MD; and Robert J. Desnick, PhD, MD
Ann Intern Med March 15, 2005 142:439-450

The following link assists in providing formally accepted medical definitions.

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