Hepatic porphyrias

Acute intermittent porphyria (AIP)
The underlying cause is an AD hereditary defect of hydroxymethylbilane synthase (also known as porphobilinogen deaminase, PBGD or uroporphyrinogen I synthase) leading to accumulating hem precursors in the liver. It manifests in an acute attack after exposure to certain chemicals (steroids, drugs, alcohol), starvation, infection or stress; mostly in the period after puberty. The main symptoms are abdominal pain (imitating NPB), constipation, vomiting, hypertension and mental problems (hysteria), headaches, paresis and plegia. There is an increased level of ALA and PBG in the urine. The blood is associated with hyponatremia, hypokalaemia with abnormalities in the metabolism of sugars and fats. The diagnosis is confirmed by decreased activity of PBGD in erythrocytes.

Therapy: in the acute phase = infusion with glukose (inhibits ALA-synthase) and hematin; prevention of another attack is to avoid the triggering factor (certain drugs or alcohol).

Porphyria from 5-aminolevulinic acid dehydratase deficiency (ADP, Doss porphyria)
It is caused by an AR hereditary 5-aminolevulinic acid dehydratase deficiency

Symptoms are abdominal pain and neuropsychic difficulties. ALA and coproporphyrin are present in the urine.

Hereditární koproporfyrie (HCP)
Vzniká AD dědičným defektem koproporfyrinogenoxidasy.

Symptomy zahrnují neuropsychické potíže, fotosenzitivitu, vzácně abdominální bolest, avšak časté jsou i naprosto asymptomatické formy. V akutním stádiu jsou v moči zvýšené hladiny ALA, PBG, koproporfyrinu (ten je také prokazatelný ve stolici).

Porfyria variegata (VP)
Etiologie je AD dědičný defekt protoporfyrinogenoxidasy.¨

Symptomy jsou abdominální bolest, neuropsychické potíže a u některých postižených také kožní příznaky (fotosenzitivita). V moči prokazatelné vysoké hodnoty ALA, PBG, koproporfyrinu; ve stolici zvýšená exkrece protoporfyrinu a koproporfyrinu. {{Netisknout|

Externí odkazy

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