congenital erythropoietic porphyria

porphyria /por·phy·ria/ (por-fēr´e-ah) any of a group of disturbances of porphyrin metabolism characterized by increase in formation and excretion of porphyrins or their precursors.

---

acute intermittent porphyria  (AIP) hereditary hepatic porphyria due to a defect of pyrrole metabolism, with recurrent attacks of abdominal pain, gastrointestinal and neurologic disturbances, and excessive amounts of δ-aminolevulinic acid and porphobilinogen in the urine.

congenital erythropoietic porphyria  (CEP) a form of erythropoietic porphyria, with cutaneous photosensitivity leading to mutilating lesions, hemolytic anemia, splenomegaly, excessive urinary excretion of uroporphyrin and coproporphyrin, and invariably erythrodontia and hypertrichosis.

porphyria cuta´nea tar´da  (PCT) a form characterized by cutaneous sensitivity that causes scarring bullae, hyperpigmentation, facial hypertrichosis, and sometimes sclerodermatous thickenings and alopecia; it is associated with reduced activity of an enzyme of heme synthesis.

erythropoietic porphyria  that in which excessive formation of porphyrin or its precursors occurs in bone marrow normoblasts, including congenital erythropoietic porphyria and erythropoietic protoporphyria.

hepatic porphyria  that in which the excess formation of porphyrin or its precursors occurs in the liver.

hepatoerythropoietic porphyria  (HEP) a severe form of porphyria cutanea tarda believed to result from a lack of activity of the enzyme catalyzing the conversion of uroporphyrinogen to coproporphyrinogen in the biosynthesis of heme.

variegate porphyria  (VP) a hereditary hepatic porphyria, with chronic skin manifestations, chiefly extreme mechanical fragility of the skin, mainly of areas exposed to sunlight, episodes of abdominal pain, neuropathy, and typically an excess of coproporphyrin and protoporphyrin in bile and feces.

---

congenital erythropoietic porphyria

n. Abbr. CEP

Enhanced porphyrin formation by erythroid cells in bone marrow, leading to severe porphyrinuria, often with hemolytic anemia and persistent cutaneous photosensitivity. Also called Günther's disease.

---

congenital erythropoietic porphyria

Etymology: L, congenitus, born with; Gk, erythros, red, poein, to make, porphyros, purple

a rare autosomal-recessive trait caused by a defect in hemoglobin synthesis in erythrocytes and release of porphyrin from normoblasts in the bone marrow. Symptoms may include mutilating lesions, hemolytic anemia, splenomegaly, excessive urinary excretion of uroporphyrin and coproporphyrin, and invariably erythrodontia and hypertrichosis.

---

porphyria [por-fēr´e-ah]

a genetic disorder characterized by a disturbance in porphyrin metabolism with resultant increase in the formation and excretion of porphyrins (uroporphyrin and coproporphyrin) or their precursors; called also hematoporphyria. Porphyrins, in combination with iron, form hemes, which in turn combine with specific proteins to form hemoproteins. hemoglobin is a hemoprotein, as are many other substances essential to normal functioning of the cells and tissues of the body.

Two general types are known: the erythropoietic porphyrias, which are concerned with the formation of erythrocytes in the bone marrow; and the hepatic porphyrias, which are responsible for liver dysfunction. Manifestations of porphyria include gastrointestinal, neurologic, and psychologic symptoms, cutaneous photosensitivity, pigmentation of the face (and later of the bones), and anemia with enlargement of the spleen. Large amounts of porphyrins are excreted in the urine and feces.

Treatment of this condition has been primarily symptomatic and varies in its effectiveness. Emphasis is on prevention of attacks by avoiding fasting and drugs that precipitate the symptoms. Photosensitivity may be controlled by avoiding exposure to light. Removal of the spleen is useful in some cases of the erythropoietic type of porphyria. Drug therapy includes the use of phenothiazines, chlorpromazine and promazine in particular. These drugs allay pain and nervousness and apparently allow a period of remission from symptoms. Meperidine hydrochloride (Demerol) may be given for pain and hydroxypheme (Hemetin) is given intravenously to compensate for genetic impairment of heme synthesis.

Patients with porphyria must not be given barbiturates, sulfonamides, alcohol, or chloroquine as these chemicals may precipitate or intensify attacks. It is recommended that persons with this disease carry with them at all times identification saying that they have porphyria so that in an emergency they will not be given medication that could precipitate an attack or even death.

acute intermittent porphyria (AIP) a hereditary, autosomal dominant, form of hepatic porphyria manifested by recurrent attacks of abdominal pain, gastrointestinal dysfunction, and neurologic disturbances, and by excessive amounts of δ-aminolevulinic acid and porphobilinogen in the urine; it is due to an abnormality of pyrrole metabolism. Called also intermittent acute porphyria.

congenital erythropoietic porphyria (CEP) a form of erythropoietic porphyria, with cutaneous photosensitivity leading to mutilating lesions, hemolytic anemia, splenomegaly, excessive urinary excretion of uroporphyrin and coproporphyrin, and invariably erythrodontia and hypertrichosis. Called also Günther disease.

porphyria cuta´nea tar´da (PCT) the most common form of porphyria, characterized by cutaneous photosensitivity that causes scarring bullae, discoloration, growth of facial hair, and sometimes sclerodermatous thickenings and alopecia; it is frequently associated with alcohol abuse, liver disease, or hepatic siderosis. Urinary levels of uroporphyrin and coproporphyrin are increased. There are two main types: an autosomal dominant (or familial ) form in which activity of the affected enzyme is reduced to half normal in liver, erythrocytes, and fibroblasts; and a sporadic (but probably also familial) form in which the reduction is confined to the liver. Both types are believed to be heterozygous and clinical expression occurs in adulthood, precipitated by disease or environmental factors. A more severe homozygous form begins in childhood and is called hepatoerythropoietic porphyria.

erythropoietic porphyria porphyria in which excessive formation of porphyrin or its precursors occurs in bone marrow erythroblasts; the group includes congenital erythropoietic porphyria and erythropoietic protoporphyria.

hepatic porphyria porphyria in which the excess formation of porphyrin or its precursors is found in the liver; it includes acute intermittent porphyria, variegate porphyria, and hereditary coproporphyria.

hepatoerythropoietic porphyria (HEP) a severe homozygous form of porphyria cutanea tarda believed to result from an autosomal dominant defect in the same enzyme as is affected in porphyria cutanea tarda; it is clinically identical to that disease but onset is in early childhood and enzyme activity in liver, erythrocytes, and fibroblasts is virtually absent.

intermittent acute porphyria acute intermittent porphyria.

porphyria variega´ta (variegate porphyria (VP)) a hereditary, autosomal dominant, type of hepatic porphyria characterized by chronic cutaneous manifestations, notably extreme mechanical fragility of the skin, particularly areas exposed to the sunlight, and by episodes of abdominal pain and neuropathy. There is typically an excess of coproporphyrin and protoporphyrin in the bile and feces.

---

congenital

present at and existing from the time of birth.

---

congenital articular rigidity

see arthrogryposis.

congenital defects

abnormalities of structure or function which are present at birth. They may or may not be inherited. There are a number of diseases, for example the lysosomal storage diseases, which may be inherited or environmental in causation, in which the insult is supplied while the fetus is in utero, but the defect does not become apparent until some time after birth. By definition these are not congenital defects although the animal is born with the metabolic lesion in place. See also individual defects listed by organ or system.

congenital erythropoietic porphyria

see porphyria.

infectious congenital tremor

see congenital tremor syndrome of piglets.

congenital loco

a congenital, inherited disease of domestic chickens characterized by opisthotonos, orthotonos, inability to stand, violent somersaulting. Affected birds die of starvation and dehydration.