Porphyria
Description:
Porphyrias (diseases porphyrinic) — hereditary or acquired (as result of influence of chemical agents) defects of the enzymes participating in biosynthesis gem.
Porphyrias classify depending on primary localization of disturbance of synthesis of porphyrines:
• The erythropoietic porphyria is caused by disturbance of synthesis of porphyrines erythroblasts of marrow and is shown mainly by a skin photosensitization (owing to activation of Ural federal district of the increased adjournment of porphyrines in skin).
• The hepatic porphyria is caused by disturbance of synthesis of porphyrines in a liver and is shown mainly by acute neurologic disorders (attacks of arterial hypertension, colic in a stomach, psychoses and neuropathies) without skin photosensitization. During an attack in plasma and urine concentration of predecessors of porphyrine - aminolevulinic acid and porphobilinogen increases.
• The mixed options.
Porphyria symptoms:
Genetic types
- Erythropoietic porphyrias
- A porphyria inborn erythropoietic (*263700, 10q25.2-q26.3, defect of a gene of UROS, p) - increase in formation of porphyrine erythroidal cells in marrow owing to insufficiency уропорфироген the III kosintetaza. Clinically: a photosensitization, a hypertrichosis, hemorrhagic diathesis (at the expense of thrombocytopenia), neonatal jaundice, a gepatosplenomegaliya, reddening of teeth, a delay of physical and mental development. Laboratory: hemolitic anemia, thrombocytopenia, a hamaturia, detection in plasma, erythrocytes, urine and Calais an uroporfi-rin of I and coproporphyrin I; decrease of the activity уропорфироген the III kosintetaza (with increase in formation of protoporphyrin III). Treatment: hemotransfusions, a splenectomy, V-carotene, antibacterial therapy of the accompanying infectious complications. Synonyms: Günter's disease, inborn porphyria (устаревш.), uroporfiriya erythropoietic.
- An erythropoietic protoporphyria (*177000, 18q21.3, defects of genes of FECH, FCE, R or p) owing to partial insufficiency of a ferrokhelataza. The most frequent erythropoietic porphyria and a porphyria, the second for frequency (after a late skin porphyria) Clinically: photosensitive dermatitis, a cholestasia with jaundice, hemolitic anemia, polyneuropathies (paresis is possible), the beginning of a disease - usually to 10-year age. Laboratory: increase in content of protoporphyrins in bile, excrements (but not in urine), decrease of the activity of a ferrokhelataza. Treatment: V-carotene, a splenectomy (at a considerable splenomegaly), hemotransfusions.
- Hereditary sideroblastny anemia.
- Hepatic porphyrias.
- A porphyria owing to insufficiency 6-aminolevulinat dehydratases (*125270, 9q34, defect of rmaALAD, p) with increase in level - aminolevulinic acid.
- A porphyria acute alternating owing to insufficiency гидроксиметилбилан sintetaza, porphobilinogen of a deaminase and уропорфироген sintetaza (*176000, Ilq23.3, defects of genes of HMBS, PBGD, UPS, R). In urine 8-aminole-vulinovoy acids are also raised contents that probably testifies to the accompanying insufficiency 5-aminolevulinat dehydratases. The prevailing floor - women's. Symptomatic treatment. At an attack:
- Glucose in/in 400 g/days
- Hematin in/in slowly in a dose of 1-4 mg/kg/days during 3-14 days. Synonyms: acute intermittent porphyria, acute porphyria. Note. Wang / ogstra-gave from the attacks of the acute alternating porphyria provoked by starvation and abuse of absinthe liqueur.
- A hereditary koproporfiriya (*121300,3ql2, defect of a gene of SRO, ZD owing to insufficiency копропорфириноген oxidases. Clinically: abdominal pains, lock, gepatosplenomegaliya, jaundice, skin photosensitization, neurologic symptomatology, hemolitic anemia. Laboratory: excess content of coproporphyrin is III in urine and Calais, hyperactivity of a sintetaza of 5-aminolevulinic acid (KF 2.3.1.37); during an attack the content of porphobilinogen and 5-aminolevulinic acid increases in urine.
- A porphyria skin late (*176100, 1r34, defect of a gene of UROD, R) - the most frequent form of a porphyria caused by insufficiency уропорфироген decarboxylases or in a liver (type I, sporadic, a gepatokozhny porphyria, 176090, R), or in other fabrics (type II, family, in so-called a gepatoeritropoetichesky porphyria), shown at adults photosensitive dermatitis in combination with the raised excretion of an uroporfirin with urine. At patients the risk of development of cancer of liver is increased. Treatment - repeated phlebotomies. Synonyms: symptomatic porphyria, hematoporphyria chronic (устар.), porfirinopatiya, epidermolysis violent porfiricheskiya.
- The porphyria mixed (176200, Iq21-q23, a gene mutation протопорфириноген oxidases of PPOX [600923], R) is characterized by a skin photosensitization, a hyperpegmentation, a hypertrichosis, abdominal pains, locks, tachycardia, arterial hypertension, various neurologic symptomatology and increase in excretion proto - and coproporphyrin with a stake. Treatment - as at the acute alternating porphyria.
- A porphyria, the Chester type (* 7ShO, Ilq23.1, defect the genaporc-kind of a porphyria which is clinically characterized by acute neurologic symptomatology without skin photosensitization. Laboratory: insufficiency erythrocyte deaminase porphobilinogen (as at the acute alternating porphyria) and протопорфириноген oxidases (as at the mixed porphyria).
Porphyria reasons:
Risk factors:
- Reception of group of companies, oral contraceptives and some other HP (for example, barbiturates and streptocides)
- Alcohol abuse
- Starvation
- Infections
- Genetic predisposition
Treatment of the Porphyria:
Treatment of a protoporphyria erythropoietic:
* to avoid stay in the sun;
* photoprotective equipment;
* холестирамин (12-16 g/days).
Treatment of a late skin porphyria:
* elimination of provocative factors.
* Appoint small doses of hingaminovy drugs.
* Outwardly - epithelizing and photoprotective equipment.
