Various clinical and biochemical observations point to a relationship between degree of disease expression and metabolic disturbance in autosomal recessive congenital erythropoietic porphyria (Günther's disease). Although the clinical manifestations have been well described since Günther's fundamental observations, an interdependence between disease severity and porphyrin excess has yet to be elucidated. We investigated porphyrin metabolism in nine Indian patients suffering from the characteristic clinical symptoms: skin photosensitivity, red-colored urine as a sign of extremely elevated porphyrinuria and mild to severe hemolytic anemia. Porphyrins in urine, feces and blood were analysed by HPTLC and HPLC in conjunction with spectrophotometry and spectrofluorometry. Uroporphyrinogen III synthase activities in red blood cells were determined using a coupled-enzyme assay. Biochemical studies revealed varying degrees of porphyrinuria with total urinary porphyrins between 23 and 102 mumol/24 h (normal < 0.2 mumol/24 h) and uroporphyrin predominance. Urinary and fecal coproporphyrin isomer I were markedly elevated to 87-97% and 81-93% (normal < 31%, < 75%), respectively. Overproduction of porphyrins led to a considerable porphyrinemia with mainly copro- and protoporphyrin. A hitherto undescribed fecal porphyrin pattern with increased protoporphyrin levels was found in three patients. This atypical finding was probably related to severe hemolysis since protoporphyrin can be excreted only via the liver with bile in the feces. High porphyrin levels in urine, feces and blood were associated with worse cutaneous symptoms. Activities of uroporphyrinogen III synthase in red blood cell lysates were decreased to between 9% and 30% of controls. Patients showed increased porphobilinogen deaminase activities, up to 190% of control. Deficiency of uroporphyrinogen III synthase activity was reflected by inversion of the relationship between and isomer III leading to dominance of isomer I. Elevation of porphobilinogen deaminase activities is related to hemolysis and, additionally, to regulatory compensation for the enzyme deficiency. Variations in both the severity of photosensitivity and the enhancement of porphyrin production and excretion indicate the molecular heterogeneity of this disease. These findings suggest a close relationship between the metabolic disturbance reflected by porphyrin excess and the severity of disease expression.

Porphyria cutanea tarda (PCX) is characterized by cutaneous symptoms in association with hepatic accumulation and urinary excretion of mainly uro- and heptacarboxyporphyrins. 24 PCX patients excreting urinary porphyrins between 1.9 and 5.8 µmol/24 h (normal < 0.2) were treated with chloroquine at a dose of 125 mg twice a week. During the first phase of therapy urinary porphyrin excretion transiently increased 1.1- to 2.9-fold indicating a phase of mobilization. A slight initial elevation was also found regarding the activities of serum amino-transferases reflecting the hepatotoxic effect of chloroquine. Xhe clinical symptoms disappeared after a period ranging from 2 to 6 months, and after an average of 12 months the porphyrin excretion in all patients had returned to nearly normal values.

Congenital erythropoietic porphyria (CEP), a rare autosomal recessive inborn error of heme biosynthesis, results from reduced activity of uroporphyrinogen III synthase (URO-III-S) leading to an excessive production and accumulation of porphyrins. Various clinical and biochemical observations point to a relationship between degree of disease expression and metabolic disturbance. We investigated 20 patients with early onset of clinical symptoms of CEP and, additionally, the relatives of six patients. CEP was confirmed by porphyrinemia and porphyrinuria with dominance of uroporphyrin and its isomer I. The investigation of the immunological nature of the defective URO-III-S gene from unrelated patients with unknown mutations was possible thanks to an antibody against the human enzyme. URO-III-S concentration in erythrocytes was determined by ELISA. No signal was achieved when assaying nonimmune serum by ELISA, whereas there was a positive reaction with the serum after immunisation. Furthermore, specificity of immune sera is demonstrated by immunoprecipitation of URO-III-S activity which caused a 33% reduction of enzyme activity. Normal levels of immunoreactive enzyme protein 100 Ϯ10% of control (x ϮSD, n ϭ 12) with a reduced specific activity 15Ϯ8.5 % (x ϮSD, n ϭ 12) were found in erythrocytes from all patients, with the exception of a girl with a remarkably high enzyme concentration of 149% of controls and a very low specific activity of 4 %. In consequence, all patients had cross-reacting immunological material (CRIM)-positive mutations. CRIM-ratios varied between 3.2 and 24.5. The CRIM-positive nature of the gene defect indicated that the mutations altered the activity of URO-III-S. The different CRIM ratios implied the presence of various mutations, which is further evidence for the heterogeneity in the genetic defect found in CEP. URO-III-S activity was determined in erythrocyte lysates by a coupled enzyme assay. Erythrocyte URO-III-S activities of patients were reduced to 4Ϫ33% of the normal value (1.72 Ϯ 0.14 pkat/mg protein). An increase of urinary coproporphyrin isomer I (40Ϫ 61%, norm ϭ 17Ϫ31%) and a halved URO-III-S activity can serve as a biochemical test for asymptomatic heterozygous gene carriers of CEP.Keywords : congenital erythropoietic porphyria ; uroporphyrinogen III synthase.Congenital erythropoietic porphyria (CEP), classically known as Günther's disease, is an autosomal recessive inborn error of heme biosynthesis which results from a 80Ϫ90% decreased activity of uroporphyrinogen III synthase (URO-III-S), the fourth enzyme of the heme biosynthetic pathway. The enzyme deficiency leads to an excessive production, accumulation and excretion of predominantly type I porphyrins, which clinically induce severe cutaneous photodermatosis mostly in association with a hemolytic process. Usually, the disease becomes obvious in early childhood [1,2]. However, a few cases have been reported in patients with late onset of photosensitivity [3]. Furthermore, dual deficiency of URO-III-S and coproporphy- rinogen ...

A hitherto undescribed dual deficiency of uroporphyrinogen III synthase and uroporphyrinogen decarboxylase was observed in the erythrocytes in a 14 year-old patient who had presented with congenital erythropoietic porphyria since early childhood. Whereas congenital erythropoietic porphyria was metabolically and clinically overt, a hereditary deficiency of uroporphyrinogen decarboxylase was confirmed by family study. The uroporphyrinogen III synthase activity of the propositus was decreased to 26% of the control while his asymptomatic family members had activities between 53-65% of the control. Additionally, the uroporphyrinogen decarboxylase activity was 55-66% of the control in the patient and his family. Family investigations have shown that the two disorders do not consistently segregate together. Although urinary porphyrin excretions of relatives were in the physiological range, the proportion of coproporphyrin isomer I showed a relative increase, which can serve as a biochemical indicator for heterozygous uroporphyrinogen III synthase gene carriers. Brought to you by | University of Queensland -UQ Library Authenticated Download Date | 7/15/15 7:30 AM Brought to you by | University of Queensland -UQ Library Authenticated Download Date | 7/15/15 7:30 AM

In Europe, hereditary coproporphyria (HCP) is the third commonest acute hepatic porphyria after acute intermittent porphyria and variegate porphyria. It is inherited as an autosomal dominant trait and excessive excretion of coproporphyrin (copro) III in faeces is the striking biochemical abnormality.' Its clinical expression, with an increase in urinary (j-aminolaevulinic acid (ALA), porphobilinogen (PBG) and porphyrins, is characterized by neurovisceral and cutaneous symptoms. PATIENTS AND METHODSA IO-year old girl presented with skin symptoms of easy fragility, scars on hands and feet, and local reddening. Father (42 years) and mother (46 years) were clinically asymptomatic. The child's teeth were light brown and exhibited red fluorescence under long-wave ultraviolet (UV) light. Congenital erythropoietic porphyria (CEP; Giinther's disease) was suspected.ALA and PBG were determined spectrophotometrically after isolation by ion-exchange chromatography. Porphyrins were analysed spectrophotometrically as methyl esters after separation by high-performance thin-layer chromatography.' Porphyrin isomers and zinc protoporphyrin were determined by highperformance liquid chromatography (HPLC).3-5Teeth were homogenized with a mortar and pestle in 1·5 mol/L HCI. The extract was freezedried and porphyrins were quantified as described above." Uroporphyrinogen III synthase, ALA dehydratase, PBG deaminase and uroporphyrinogen decarboxylase were studied in erythrocytes.? Coproporphyrinogen