Jaundice, also known as icterus, is a yellowish or greenish pigmentation of the skin and whites of the eyes due to high bilirubin levels. It is commonly associated with itchiness. The feces may be pale and the urine dark. Jaundice in babies occurs in over half in the first week following birth and does not pose a serious threat in most. If bilirubin levels in babies are very high for too long, a type of brain damage, known as kernicterus, may occur.
Porphyria is a group of diseases in which substances called porphyrins build up, negatively affecting the skin or nervous system. The types that affect the nervous system are also known as acute porphyria, as symptoms are rapid in onset and last a short time. Symptoms of an attack include abdominal pain, chest pain, vomiting, confusion, constipation, fever, high blood pressure, and high heart rate. The attacks usually last for days to weeks. Complications may include paralysis, low blood sodium levels, and seizures. Attacks may be triggered by alcohol, smoking, hormonal changes, fasting, stress, or certain medications. If the skin is affected, blisters or itching may occur with sunlight exposure.
Glucose-6-phosphate dehydrogenase deficiency (G6PDD) is an inborn error of metabolism that predisposes to red blood cell breakdown. Most of the time, those who are affected have no symptoms. Following a specific trigger, symptoms such as yellowish skin, dark urine, shortness of breath, and feeling tired may develop. Complications can include anemia and newborn jaundice. Some people never have symptoms.
Hereditary spherocytosis is an abnormality of red blood cells, or erythrocytes. The disorder is caused by mutations in genes relating to membrane proteins that allow for the erythrocytes to change shape. The abnormal erythrocytes are sphere-shaped (spherocytosis) rather than the normal biconcave disk shaped. Dysfunctional membrane proteins interfere with the cell's ability to be flexible to travel from the arteries to the smaller capillaries. This difference in shape also makes the red blood cells more prone to rupture. Cells with these dysfunctional proteins are degraded in the spleen. This shortage of erythrocytes results in hemolytic anemia.
Hereditary coproporphyria (HCP) is a disorder of heme biosynthesis, classified as an acute hepatic porphyria. HCP is caused by a deficiency of the enzyme coproporphyrinogen oxidase, coded for by the CPOX gene, and is inherited in an autosomal dominant fashion, although homozygous individuals have been identified. Unlike acute intermittent porphyria, individuals with HCP can present with cutaneous findings similar to those found in porphyria cutanea tarda in addition to the acute attacks of abdominal pain, vomiting and neurological dysfunction characteristic of acute porphyrias. Like other porphyrias, attacks of HCP can be induced by certain drugs, environmental stressors or diet changes. Biochemical and molecular testing can be used to narrow down the diagnosis of a porphyria and identify the specific genetic defect. Overall, porphyrias are rare diseases. The combined incidence for all forms of the disease has been estimated at 1:20,000. The exact incidence of HCP is difficult to determine, due to its reduced penetrance.
Pyruvate kinase deficiency is an inherited metabolic disorder of the enzyme pyruvate kinase which affects the survival of red blood cells. Both autosomal dominant and recessive inheritance have been observed with the disorder; classically, and more commonly, the inheritance is autosomal recessive. Pyruvate kinase deficiency is the second most common cause of enzyme-deficient hemolytic anemia, following G6PD deficiency.
Gunther disease, is a congenital form of erythropoietic porphyria. The word porphyria originated from the Greek word porphura. Porphura actually means "purple pigment", which, in suggestion, the color that the body fluid changes when a person has Gunther's disease. It is a rare, autosomal recessive metabolic disorder affecting heme, caused by deficiency of the enzyme uroporphyrinogen cosynthetase. It is extremely rare, with a prevalence estimated at 1 in 1,000,000 or less. There have been times that prior to birth of a fetus, Gunther's disease has been shown to lead to anemia. In milder cases patients have not presented any symptoms until they have reached adulthood. In Gunther's disease, porphyrins are accumulated in the teeth and bones and an increased amount are seen in the plasma, bone marrow, feces, red blood cells, and urine.
Acute intermittent porphyria (AIP) is a rare autosomal dominant metabolic disorder affecting the production of heme resulting from a deficiency of the porphobilinogen deaminase. It is the most common of the acute porphyrias.
Crigler–Najjar syndrome is a rare inherited disorder affecting the metabolism of bilirubin, a chemical formed from the breakdown of the heme in red blood cells. The disorder results in a form of nonhemolytic jaundice, which results in high levels of unconjugated bilirubin and often leads to brain damage in infants. The disorder is inherited in an autosomal recessive manner.
Protoporphyrinogen oxidase is an enzyme that in humans is encoded by the PPOX gene.
Fumarase deficiency is an exceedingly rare autosomal recessive metabolic disorder in Krebs cycle characterized by a deficiency of the enzyme fumarate hydratase, which causes a buildup of fumaric acid in the urine, and a deficiency of malate. Only 13 cases were known worldwide in 1990, after which a cluster of 20 cases was documented in an inbred community in Arizona.
Coproporphyrinogen-III oxidase, mitochondrial is an enzyme that in humans is encoded by the CPOX gene. A genetic defect in the enzyme results in a reduced production of heme in animals. The medical condition associated with this enzyme defect is called hereditary coproporphyria.
Ferrochelatase (or protoporphyrin ferrochelatase) is an enzyme that is encoded by the FECH gene in humans. Ferrochelatase catalyses the eighth and terminal step in the biosynthesis of heme, converting protoporphyrin IX into heme B. It catalyses the reaction:
Erythropoietic porphyria is a type of porphyria associated with erythropoietic cells. In erythropoietic porphyrias, the enzyme deficiency occurs in the red blood cells.
Hepatoerythropoietic porphyria is a very rare form of hepatic porphyria caused by a disorder in both genes which code Uroporphyrinogen III decarboxylase (UROD).
Triosephosphate isomerase deficiency is a rare autosomal recessive metabolic disorder which was initially described in 1965.
Aldolase A deficiency, is an autosomal recessive metabolic disorder resulting in a deficiency of the enzyme aldolase A; the enzyme is found predominantly in red blood cells and muscle tissue. The deficiency may lead to hemolytic anaemia as well as myopathy associated with exercise intolerance and rhabdomyolysis in some cases.
PRP31 pre-mRNA processing factor 31 homolog , also known as PRPF31, is a protein which in humans is encoded by the PRPF31 gene.
Aminolevulinic acid dehydratase deficiency porphyria is a neuropsychiatric condition. The disease can present during early childhood with acute neurologic symptoms that resemble those encountered in acute intermittent porphyria.
