ABSTRACT
The porphyrias are a diverse group of metabolic disorders arising from diminished
activity of enzymes in the heme biosynthetic pathway. They can present with acute
neurovisceral symptoms, cutaneous symptoms, or both. The complexity of these
disorders is demonstrated by the fact that some acute porphyria patients with the
underlying genetic defect(s) are latent and asymptomatic while others present with
severe symptoms. This indicates that there is at least one other risk factor required in
addition to the genetic defect for symptom manifestation. A systematic review of the
heme biosynthetic pathway highlighted the involvement of a number of micronutrient
cofactors. An exhaustive review of the medical literature uncovered numerous reports
of micronutrient deficiencies in the porphyrias as well as successful case reports of
treatments with micronutrients. Many micronutrient deficiencies present with
symptoms similar to those in porphyria, in particular vitamin B6. It is hypothesized
that a vitamin B6 deficiency and related micronutrient deficiencies may play a major
role in the pathogenesis of the acute porphyrias. In order to further investigate the
porphyrias, a computational model of the heme biosynthetic pathway was developed
based on kinetic parameters derived from a careful analysis of the literature. This
model demonstrated aspects of normal heme biosynthesis and illustrated some of the
disordered biochemistry of acute intermittent porphyria (AIP). The testing of this
model highlighted the modifications necessary to develop a more comprehensive
model with the potential to investigated hypotheses of the disordered biochemistry of
the porphyrias as well as the discovery of new methods of treatment and symptom
control. It is concluded that vitamin B6 deficiency might be the risk factor necessary
in conjunction with the genetic defect to trigger porphyria symptoms.
| Identifer | oai:union.ndltd.org:canterbury.ac.nz/oai:ir.canterbury.ac.nz:10092/10257 |
| Date | January 2014 |
| Creators | Ruegg, Evonne Teresa Nicole |
| Publisher | University of Canterbury. Biochemistry |
| Source Sets | University of Canterbury |
| Language | English |
| Detected Language | English |
| Type | Electronic thesis or dissertation, Text |
| Rights | Copyright Evonne Teresa Nicole Ruegg, http://library.canterbury.ac.nz/thesis/etheses_copyright.shtml |
| Relation | NZCU |
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