Aceruloplasminemia | |
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Other names | Ceruloplasmin deficiency [1] |
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MRI hypointensity (white arrows) in the globus pallidi that indicates the presence of iron deficiencies which would be seen in a diagnosis of Aceruloplasminemia | |
Specialty | Medical genetics |
Aceruloplasminemia is a rare autosomal recessive disorder [2] in which the liver can not synthesize the protein ceruloplasmin properly, which is needed to transport copper around the blood. Copper deficiency in the brain results in neurological problems that generally appear in adulthood and worsen over time. [3]
Aceruloplasminemia has been seen worldwide, but its overall prevalence is unknown. Studies in Japan have estimated that approximately 1 in 2 million adults in this population are affected. [4]
Aceruloplasminemia belongs to the group of genetic disorders called neurodegeneration with brain iron accumulation (NBIA).
Patients with aceruloplasminemia develop a variety of movement problems. They may experience dystonia of the head and neck, resulting in repetitive movements and contortions. Other involuntary movements may also occur, such as tremors, chorea, blepharospasms, and grimacing. Affected individuals may also experience ataxia, the lack of coordination of muscle movements. Some develop psychiatric problems and midlife dementia. [4] The type of neurological disruption corresponds to associated regions of iron deposition in the brain and liver. [5]
In addition to neurological problems, affected individuals may have diabetes mellitus caused by iron damage to cells in the pancreas that make insulin. This impairs blood sugar regulation and leads to the signs and symptoms of diabetes. [4]
Iron accumulation in the tissues and organs results in a corresponding iron deficiency in the blood, leading to anemia. Anemia and diabetes usually occur by the time an affected person is in his or her twenties. [4]
Affected individuals also experience retinal degeneration caused by excess iron. The changes result in small opaque spots and areas of atrophy around the edges of the retina. These abnormalities usually do not affect vision but can be observed during an eye examination. [4]
Aceruloplasminemia is caused by a mutation (a five-base pair insertion in exon 7 [3] ) in the CP gene, which provides instructions for making a protein called ceruloplasmin, a protein involved in iron transport and processing. Ceruloplasmin helps move iron from the organs and tissues of the body and prepares it for incorporation into a molecule called transferrin, which transports it to red blood cells to help carry oxygen. The CP gene mutation results in the production of ceruloplasmin protein that is unstable or nonfunctional by altering the open reading frame such that the amino acid ligands in the essential carboxyl terminal region are eliminated. [3] When ceruloplasmin is unavailable, transport of iron out of the body's tissues is impaired. The resulting iron accumulation damages cells in those tissues, leading to neurological dysfunction and other health problems. [4] [6]
This condition is inherited in an autosomal recessive pattern, which means both copies of the gene have the mutation. The parents of an individual with an autosomal recessive condition each carry one copy of the mutated gene, but they typically do not show signs and symptoms of the condition. [4]
Diagnosis of this disorder depends on blood tests demonstrating the absence of serum ceruloplasmin, combined with low serum copper concentration, low serum iron concentration, high serum ferritin concentration, or increased hepatic iron concentration. MRI scans can also confirm a diagnosis; abnormal low intensities can indicate iron accumulation in the brain. [5]
Children of affected individuals are obligate carriers for aceruloplasminemia. If the CP mutations has been identified in a related individual, prenatal testing is recommended. Siblings of those affected by the disease are at a 25% risk of aceruloplasminemia. In asymptomatic siblings, serum concentrations of hemoglobin and hemoglobin A1c should be monitored. [5]
To prevent the progression of symptoms of the disease, annual glucose tolerance tests beginning in early teen years to evaluate the onset of diabetes mellitus. Those at risk should avoid taking iron supplements. [5]
Treatment includes the use of iron chelating agents (such as desferrioxamine) to lower brain and liver iron stores, and to prevent progression of neurologic symptoms. This, combined with fresh-frozen human plasma (FFP) works effectively in decreasing liver iron content. Repetitive use of FFP can even improve neurologic symptoms. Antioxidants such as vitamin E can be used simultaneously to prevent tissue damage to the liver and pancreas. [5]
Wilson's disease is a genetic disorder characterized by the excess build-up of copper in the body. Symptoms are typically related to the brain and liver. Liver-related symptoms include vomiting, weakness, fluid build-up in the abdomen, swelling of the legs, yellowish skin, and itchiness. Brain-related symptoms include tremors, muscle stiffness, trouble in speaking, personality changes, anxiety, and psychosis.
Hereditary haemochromatosis type 1 is a genetic disorder characterized by excessive intestinal absorption of dietary iron, resulting in a pathological increase in total body iron stores. Humans, like most animals, have no mechanism to regulate excess iron, simply losing a limited amount through various means like sweating or menstruating.
Iron overload is the abnormal and increased accumulation of total iron in the body, leading to organ damage. The primary mechanism of organ damage is oxidative stress, as elevated intracellular iron levels increase free radical formation via the Fenton reaction. Iron overload is often primary but may also be secondary to repeated blood transfusions. Iron deposition most commonly occurs in the liver, pancreas, skin, heart, and joints. People with iron overload classically present with the triad of liver cirrhosis, secondary diabetes mellitus, and bronze skin. However, due to earlier detection nowadays, symptoms are often limited to general chronic malaise, arthralgia, and hepatomegaly.
Ceruloplasmin is a ferroxidase enzyme that in humans is encoded by the CP gene.
Fukuyama congenital muscular dystrophy (FCMD) is a rare, autosomal recessive form of muscular dystrophy (weakness and breakdown of muscular tissue) mainly described in Japan but also identified in Turkish and Ashkenazi Jewish patients; fifteen cases were first described on 1960 by Dr. Yukio Fukuyama.
Cystinosis is a lysosomal storage disease characterized by the abnormal accumulation of cystine, the oxidized dimer of the amino acid cysteine. It is a genetic disorder that follows an autosomal recessive inheritance pattern. It is a rare autosomal recessive disorder resulting from accumulation of free cystine in lysosomes, eventually leading to intracellular crystal formation throughout the body. Cystinosis is the most common cause of Fanconi syndrome in the pediatric age group. Fanconi syndrome occurs when the function of cells in renal tubules is impaired, leading to abnormal amounts of carbohydrates and amino acids in the urine, excessive urination, and low blood levels of potassium and phosphates.
Neuroacanthocytosis is a label applied to several genetic neurological conditions in which the blood contains misshapen, spiculated red blood cells called acanthocytes.
Glycine encephalopathy is a rare autosomal recessive disorder of glycine metabolism. After phenylketonuria, glycine encephalopathy is the second most common disorder of amino acid metabolism. The disease is caused by defects in the glycine cleavage system, an enzyme responsible for glycine catabolism. There are several forms of the disease, with varying severity of symptoms and time of onset. The symptoms are exclusively neurological in nature, and clinically this disorder is characterized by abnormally high levels of the amino acid glycine in bodily fluids and tissues, especially the cerebrospinal fluid.
Tangier disease or hypoalphalipoproteinemia is an extremely rare inherited disorder characterized by a severe reduction in the amount of high density lipoprotein (HDL), often referred to as "good cholesterol", in the bloodstream. Worldwide, approximately 100 cases have even been identified.
Carbamoyl phosphate synthetase I deficiency is an autosomal recessive metabolic disorder that causes ammonia to accumulate in the blood due to a lack of the enzyme carbamoyl phosphate synthetase I. Ammonia, which is formed when proteins are broken down in the body, is toxic if the levels become too high. The nervous system is especially sensitive to the effects of excess ammonia.
Pyruvate carboxylase deficiency is an inherited disorder that causes lactic acid to accumulate in the blood. High levels of these substances can damage the body's organs and tissues, particularly in the nervous system. Pyruvate carboxylase deficiency is a rare condition, with an estimated incidence of 1 in 250,000 births worldwide. Type A of the disease appears to be much more common in some Algonkian Indian tribes in eastern Canada, while the type B disease is more present in European populations.
Juvenile hemochromatosis, also known as hemochromatosis type 2, is a rare form of hereditary hemochromatosis, which emerges in young individuals, typically between 15 and 30 years of age, but occasionally later. It is characterized by an inability to control how much iron is absorbed by the body, in turn leading to iron overload, where excess iron accumulates in many areas of the body and causes damage to the places it accumulates.
Congenital generalized lipodystrophy is an extremely rare autosomal recessive condition, characterized by an extreme scarcity of fat in the subcutaneous tissues. It is a type of lipodystrophy disorder where the magnitude of fat loss determines the severity of metabolic complications. Only 250 cases of the condition have been reported, and it is estimated that it occurs in 1 in 10 million people worldwide.
GRACILE syndrome is a very rare lethal autosomal recessive genetic disorder, one of the Finnish heritage diseases. GRACILE syndrome has also been found in the UK and Sweden, but not nearly as much as in Finland. It is caused by a mutation in the BCS1L gene and it occurs in approximately 1 out of 50,000 live births in Finnish people. To date, there have only been 32 cases of GRACILE syndrome reported.
Neuroferritinopathy is a genetic neurodegenerative disorder characterized by the accumulation of iron in the basal ganglia, cerebellum, and motor cortex of the human brain. Symptoms, which are extrapyramidal in nature, progress slowly and generally do not become apparent until adulthood. These symptoms include chorea, dystonia, and cognitive deficits which worsen with age.
Argininemia is an autosomal recessive urea cycle disorder where a deficiency of the enzyme arginase causes a buildup of arginine and ammonia in the blood. Ammonia, which is formed when proteins are broken down in the body, is toxic if levels become too high; the nervous system is especially sensitive to the effects of excess ammonia.
Cerebral autosomal recessive arteriopathy with subcortical infarcts and leukoencephalopathy (CARASIL) is disease of the arteries in the brain, which causes tissue loss in the subcortical region of the brain and the destruction of myelin in the CNS. CARASIL is characterized by symptoms such as gait disturbances, hair loss, low back pain, dementia, and stroke. CARASIL is a rare disease, having only been diagnosed in about 50 patients, of which ten have been genetically confirmed. Most cases have been reported in Japan, but Chinese and caucasian individuals have also been diagnosed with the disease. CARASIL is inherited in an autosomal recessive pattern. There is currently no cure for CARASIL. Other names for CARASIL include familial young-adult-onset arteriosclerotic leukoencephalopathy with alopecia and lumbago without arterial hypertension, Nemoto disease and Maeda syndrome.
Hemochromatosis type 4 is a hereditary iron overload disorder that affects ferroportin, an iron transport protein needed to export iron from cells into circulation. Although the disease is rare, it is found throughout the world and affects people from various ethnic groups. While the majority of individuals with type 4 hemochromatosis have a relatively mild form of the disease, some affected individuals have a more severe form. As the disease progresses, iron may accumulate in the tissues of affected individuals over time, potentially resulting in organ damage.
Tyrosinemia type I is a genetic disorder that disrupts the metabolism of the amino acid tyrosine, resulting in damage primarily to the liver along with the kidneys and peripheral nerves. The inability of cells to process tyrosine can lead to chronic liver damage ending in liver failure, as well as renal disease and rickets. Symptoms such as poor growth and enlarged liver are associated with the clinical presentation of the disease. If not detected via newborn screening and management not begun before symptoms appear, clinical manifestation of disease occurs typically within the first two years of life. The severity of the disease is correlated with the timing of onset of symptoms, earlier being more severe. If diagnosed through newborn screening prior to clinical manifestation, and well managed with diet and medication, normal growth and development is possible.
Mitochondrial membrane protein-associated neurodegeneration (MPAN) is a genetic neurodegenerative disease that causes dystonia, parkinsonism, and iron accumulation in the brain. It is caused by mutations to the gene C19orf12, which has unknown function. This was originally discovered as an autosomal recessive disorder, caused by individuals having two mutations to the gene C19orf12, but autosomal dominant disease caused by a single mutation in the same gene has also been rarely described. Due to the common features of neurodegeneration, brain iron accumulation, and movement disorder it is classified as a neurodegeneration with brain iron accumulation (NBIA) disorder and another name for the condition is neurodegeneration with brain iron accumulation 4 (NBIA4).