- /pawr fear"ee euh, -fuy"ree euh/, n. Pathol.a defect of blood pigment metabolism in which porphyrins are produced in excess, are present in the blood, and are found in the urine. Also called hematoporphyria.[1920-25; PORPHYR(IN) + -IA]
* * *any of a group of diseases characterized by the marked overproduction and excretion of porphyrins (porphyrin) or of one or another of their precursors. The porphyrins are reddish constituents of heme, the deep red iron-containing pigment of hemoglobin, the oxygen-carrying protein of the red blood cells. The deposition of porphyrin compounds in body tissues, notably the skin, gives rise to a variety of symptoms, the nature of which depends on the specific compound that is abnormally metabolized.Two main groups of porphyria are recognized: (1) erythropoietic and (2) hepatic. In the first, the overproduction occurs in relation to hemoglobin synthesis by cells in the bone marrow; in the second, the disturbance is in the liver.There are two principal types of erythropoietic porphyria: (1) In congenital erythropoietic porphyria, or Günther's disease, the excretion of pinkish urine is noted shortly after birth; later, the skin becomes fragile, and blisters may appear in body areas exposed to light; the teeth and bones are reddish brown. Anemia and enlargement of the spleen are frequently noted. The condition is thought to be transmitted as a recessive trait. (2) In erythropoietic protoporphyria, the skin becomes inflamed and itchy after short exposures to sunlight, but usually there are no other impairments, and this form of porphyria, which is transmitted as a dominant trait, is compatible with normal life expectancy.There are three types of hepatic porphyria: (1) In acute intermittent porphyria, also called porphyria hepatica, affected persons have recurrent attacks of abdominal pain and vomiting, weakness or paralysis of the limbs, and psychic changes resembling hysteria. Attacks may be precipitated by a variety of drugs, including barbiturates and contraceptives and possibly alcohol. This condition is transmitted as a dominant trait; it is possibly the most common form of porphyria, with an overall incidence of approximately one per 100,000 population; people of Scandinavian, Anglo-Saxon, and German ancestry seem more susceptible than others. (2) In variegate porphyria, affected individuals suffer from chronic skin lesions that tend to heal slowly. Acute transient attacks of abdominal pain and nervous-system symptoms may also be present. The condition is inherited as a dominant trait, being especially common in the white population of South Africa. (3) Porphyria cutanea tarda symptomatica, or cutaneous porphyria, is more common in males and usually begins insidiously later in life, in the fourth to eighth decade. The exposed skin is fragile and sensitive to light and other factors. Liver function impairment, if the patient also suffers from chronic alcoholism, is present in the majority of affected individuals; abstinence, in alcoholic patients, results in marked improvement or disappearance of the porphyria; the tendency to develop this form of porphyria also appears to be inherited.In addition to hereditary porphyria, there have also been rare instances of acquired hepatic porphyria, caused by intoxications. There is generally no specific treatment for porphyria; therapy is aimed at alleviating the symptoms and preventing skin injury and attacks.
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porphyria — porphyria. См. порфирии. (Источник: «Англо русский толковый словарь генетических терминов». Арефьев В.А., Лисовенко Л.А., Москва: Изд во ВНИРО, 1995 г.) … Молекулярная биология и генетика. Толковый словарь.
porphyria — 1923, from porphyrin (1910), from Ger. porphyrin, chemical name, from Gk. porphyros вЂњpurpleвЂќ (see PURPLE (Cf. purple)) + IN (Cf. in) (2). Some of the compounds are purple … Etymology dictionary
porphyria — [pôr fir′ē ə] n. [ModL < PORPHYRIN + IA] an inherited disorder of pigment metabolism with excretion of porphyrins in the urine and dangerous sensitivity to sunlight … English World dictionary
Porphyria — This article is about the medical condition. For other uses, see Porphyry (disambiguation). Porphyria Classification and external resources ICD 10 E80.0 E80.2 … Wikipedia
Porphyria — Any of a group of inherited diseases characterized by skin sensitivity to sunlight and/or by intermittent acute attacks of abdominal and nerve pain. The porphyrias are caused by enzyme defects that trigger the overproduction of porphyrins by the… … Medical dictionary
porphyria — n. one of a group of rare disorders due to inborn errors of metabolism in which there are deficiencies in the enzymes involved in the biosynthesis of haem. The accumulation of the enzyme s substrate gives rise to symptoms of the disorder. The… … The new mediacal dictionary
Porphyria — (Poor FEAR ee ah) Porphyria is a rare hereditary medical condition in which a person s body does not produce heme, the main component in hemoglobin. Those who suffer with this disease have a sensitivity to sunlight, allergic reactions to GARLIC,… … Encyclopedia of vampire mythology
porphyria — n. any of a group of genetic disorders associated with abnormal metabolism of various pigments. Etymology: mod.L f. porphyrin purple substance excreted by porphyria patients f. Gk porphura purple … Useful english dictionary
porphyria — noun Etymology: New Latin, from International Scientific Vocabulary porphyrin Date: 1923 any of several usually hereditary abnormalities of porphyrin metabolism characterized by excretion of excess porphyrins in the urine … New Collegiate Dictionary
porphyria — Any of a group of disorders in which there is excessive excretion of porphyrins or their precursors … Dictionary of molecular biology