=====Porphyrias=====
  *a set of genetic (AD,AR and X-linked versions) metabolic disorders, each a defect in one of the 8 enzymes in the heme biosynthetic pathway resulting in the accumulation of precursors of heme. Porphyrins are the major precursors.
  *can be classified as hepatic or erythropoietic based on whether the heme precursors 1st accumulate in the liver or the bone marrow and red blood cells
  *also classified as acute and chronic or cutaneous porphyrias
<WRAP NOTICE ROUND 80%>**"classic triad" suggesting acute porphyria:**
  -abdominal pain
  -central nervous system abnormalities
  -peripheral neuropathy
</WRAP>
^Hepatic ^Erythropoietic ^Acute ^Chronic |
|• acute intermittent porphyria (AIP)\\ • variegate porphyria (VP)\\ • aminolevulinic acid dehydratase deficiency porphyria (ALAD)\\ • hereditary coproporphyria (HCP)\\ • porphyria cutanea tarda (PCT) |• Congenital erythropoietic porphyria\\ • Erythropoietic porphyria\\ • Hepatoerythropoietic porphyria\\ • X-linked protoporphyria |• Acute intermittent porphyria\\ • ALA dehydratase deficiency porphyria (Doss porphyria)\\ • Hereditary coproporphyria\\ • Variegate porphyria  |• Congenital erythropoietic porphyria\\ • Erythropoietic porphyria\\ • Hepatoerythropoietic porphyria\\ • Porphyria cutanea tarda\\ • X-linked protoporphyria | 
==Hepatic porphyrias==  
  ***presentation:**
      *generally neurological
      *neuropathic abdominal pain is most common presentation.
      *seizures, psychosis
      *back pain
      *acute polyneuropathy.
      *Occasionally some cutaneous manifestations.

  ***Investigations:**
    *Urine porphobilinogen (PBG)
    *Decreased erythrocyte porphobilinogen deaminase (PBGD) activity
    *commonly - hyponatraemia and raised transaminases

  ***Management:**
    *supportive - IV fluid, analgesia
    *IV haem arginate (human hemin) - 3mg/kg (to a maximum of 250mg) once daily for 4 consecutive days.

==References include:==
[[https://www.ncbi.nlm.nih.gov/books/NBK537178/|Acute Hepatic Porphyria review]]\\ 
[[https://emedicine.medscape.com/article/1389981-overview#a2|Emed porphyrias]]\\