1) Detection of orotic acid in urine

2) Deficiency of Enzymes orotate phosphoribosyl transferase and OMP decarboxylase

At present there is no specific treatment. Many patients with haemolytic anaemia take folic acid (vitamin B) since the greater turnover of cells consumes this vitamin. During crises transfusion may be required. Clotting problems can occur for which anticoagulation may be needed. Unlike hereditary spherocytosis, splenectomy is contraindicated.

Treatment consists of frequent blood transfusions and chelation therapy. Potential cures include bone marrow transplantation and gene therapy.

The diagnosis of Albright's hereditary osteodystrophy is based on the following exams below:

- CBC

- Urine test

- MRI

The anemia associated with CDA type II can range from mild to severe, and most affected individuals have jaundice, hepatosplenomegaly, and the formation of hard deposits in the gallbladder called bilirubin gallstones. This form of the disorder is usually diagnosed in adolescence or early adulthood. An abnormal buildup of iron typically occurs after age 20, leading to complications including heart disease, diabetes, and cirrhosis.

Administration of cytidine monophosphate and uridine monophosphate reduces urinary orotic acid and ameliorates the anemia.

Administration of uridine, which is converted to UMP, will bypass the metabolic block and provide the body with a source of pyrimidine.

Uridine triacetate is a drug approved by FDA to be used in the treatment of hereditary orotic aciduria.

Diagnosis of acquired dysfibrinogenemia uses the same laboratory tests that are used for congenital dysfibrinogenemia plus evidence for an underlying causative disease.

Haematologists have identified a number of variants. These can be classified as below.

- Overhydrated hereditary stomatocytosis

- Dehydrated HSt (hereditary xerocytosis; hereditary hyperphosphatidylcholine haemolytic anaemia)

- Dehydrated with perinatal ascites

- Cryohydrocytosis

- 'Blackburn' variant.

- Familial pseudohyperkalaemia

There are other families that do not fall neatly into any of these classifications.

Stomatocytosis is also found as a hereditary disease in Alaskan malamute and miniature schnauzer dogs.

No treatment is indicated for essential fructosuria, while the degree of fructosuria depends on the dietary fructose intake, it does not have any clinical manifestations. The amount of fructose routinely lost in urine is quite small. Other errors in fructose metabolism have greater clinical significance. Hereditary fructose intolerance, or the presence of fructose in the blood (fructosemia), is caused by a deficiency of aldolase B, the second enzyme involved in the metabolism of fructose. This enzyme deficiency results in an accumulation of fructose-1-phosphate, which inhibits the production of glucose and results in diminished regeneration of adenosine triphosphate. Clinically, patients with hereditary fructose intolerance are much more severely affected than those with essential fructosuria, with elevated uric acid, growth abnormalities and can result in coma if untreated.

Usually, a common form of treatment for the condition is a type of hand cream which moisturises the hard skin. However, currently the condition is incurable.

A diagnosis of essential fructosuria is typically made after a positive test for reducing substances in the urine. The excretion of fructose in the urine is not constant, it depends largely on dietary intake.

Harderoporphyria is a rare disorder of heme biosynthesis, inherited in an autosomal recessive manner caused by specific mutations in the "CPOX" gene. Mutations in "CPOX" usually cause hereditary coproporphyria, an acute hepatic porphyria, however the K404E mutation in a homozygous or compound heterozygous state with a null allele cause the more severe harderoporphyria. Harderoporphyria is the first known metabolic disorder where the disease phenotype depended on the type and location of the mutations in a gene associated with multiple disorders.

In contrast with other porphyrias, which typically present with either cutaneous lesions after exposure to sunlight or acute neurovisceral attack at any age (most commonly in adulthood), harderoporphyria is characterized by jaundice, anemia enlarged liver and spleen, often presenting in the neonatal period. Later in life, these individuals may present with photosensitivity similar to that found in cutaneous porphyrias.

Biochemically, harderoporphyria presents with a distinct pattern of increased harderoporphyrin (2-vinyl-4,6,7-tripropionic acid porphyrin) in urine and particularly in feces, a metabolite that is not seen in significant quantities in any other porphyria. Enzyme tests show markedly reduced activity of coproporphyrinogen oxidase, compared to both unaffected individuals and those affected with hereditary coproporphyria, consistent with recessive inheritance.

Harderoporphyria is a rare condition, with less than 10 cases reported worldwide. It may be underdiagnosed, as it does not have the typical presentation associated with a porphyria. It was identified as a variant type of coproporphyria in 1983, in a family with three children identified at birth with jaundice and hemolytic anemia. There is no standard treatment for harderoporphyria; care is mainly focused on the management of symptoms.

Treatment consists of maintaining normal levels of calcium, phosphorus, and Vitamin D. Phosphate binders, supplementary Calcium and Vitamin D will be used as required.

Treatment of asymptomatic congenital dysfibrinogenemia depends in part on the expectations of developing bleeding and/or thrombotic complications as estimated based on the history of family members with the disorder and, where available, determination of the exact mutation causing the disorder plus the propensity of the particular mutation type to develop these complications. In general, individuals with this disorder require regular follow-up and multidiscipline management prior to surgery, pregnancy, and giving childbirth. Women with the disorder appear to have an increased rate of miscarriages and all individuals with fibrinogen activity in clotting tests below 0.5 grams/liter are prone to bleeding and spontaneous abortions. Women with multiple miscarriages and individuals with excessively low fibrinogen activity levels should be considered for prophylaxis therapy with fibrinogen replacement during pregnancy, delivery, and/or surgery.

The disease can be treated only to slow down the development, by use of cyclosporine A and ACE inhibitors, but not stopped or cured.

There exist other causes of excess iron accumulation, which have to be considered before haemochromatosis is diagnosed.

- African iron overload, formerly known as Bantu siderosis, was first observed among people of African descent in Southern Africa. Originally, this was blamed on ungalvanised barrels used to store home-made beer, which led to increased oxidation and increased iron levels in the beer. Further investigation has shown that only some people drinking this sort of beer get an iron overload syndrome, and that a similar syndrome occurred in people of African descent who have had no contact with this kind of beer ("e.g.," African Americans). This led investigators to the discovery of a gene polymorphism in the gene for ferroportin which predisposes some people of African descent to iron overload.

- Transfusion haemosiderosis is the accumulation of iron, mainly in the liver, in patients who receive frequent blood transfusions (such as those with thalassaemia).

- Dyserythropoeisis, also known as myelodysplastic syndrome, is a disorder in the production of red blood cells. This leads to increased iron recycling from the bone marrow and accumulation in the liver.

Affected male and carrier female dogs generally begin to show signs of the disease at two to three months of age, with proteinuria. By three to four months of age, symptoms include for affected male dogs: bodily wasting and loss of weight, proteinuria & hypoalbuminemia. Past nine months of age, hypercholesterolemia may be seen. In the final stages of the disease, at around 15 months of age for affected males, symptoms are reported as being renal failure, hearing loss and death. Since the condition is genetically dominant, diagnosis would also include analysis of the health of the sire and dam of the suspected affected progeny if available.

HPFH may alleviate the severity of certain hemoglobinopathies and thalassemias, and is selected for in populations with a high prevalence of these conditions (which in turn are often selected for in areas where malaria is endemic). Thus, it has been found to affect Americans of African and Greek descent.

Genetic testing for the presence of mutations in protein molecules is considered to be a confirmatory testing technique. It is important to know the risks regarding the transmission and dangers of HPP.

Clinically the disease may be silent, but characteristic radiological features may point to the diagnosis. The increased iron stores in the organs involved, especially in the liver and pancreas, result in characteristic findings on unenhanced CT and a decreased signal intensity in MRI scans. Haemochromatosis arthropathy includes degenerative osteoarthritis and chondrocalcinosis. The distribution of the arthropathy is distinctive, but not unique, frequently affecting the second and third metacarpophalangeal joints of the hand. The arthropathy can therefore be an early clue as to the diagnosis of haemochromatosis.

First degree relatives of those with primary haemochromatosis should be screened to determine if they are a carrier or if they could develop the disease. This can allow preventive measures to be taken.

Screening the general population is not recommended.

The condition is usually asymptomatic, and is only noticed when screening for other hemoglobin disorders.

Hereditary gelsolin amyloidosis is a cutaneous condition inherited in an autosomal dominant fashion.

The condition was first described in 1969, by the Finnish ophthalmologist Jouko Meretoja, and is also known as Familial amyloid neuropathy type IV, Meretoja syndrome, Hereditary amyloidosis, Finnish type.

The disorder primarily associated with eye, skin and cranial nerve symptoms. It is a form of amyloidosis, where the amyloid complexes are formed from fragments of the protein gelsolin in the plasma, due to a mutation in the GSN gene (c.654G>A or c.654G>T).

Autosomal Dominant Retinal Vasculopathy with Cerebral Leukodystrophy (AD-RVCL) (previously known also as Cerebroretinal Vasculopathy, CRV, or Hereditary Vascular Retinopathy, HVR or Hereditary Endotheliopathy, Retinopathy, Nephropathy, and Stroke, HERNS) is an inherited condition resulting from a frameshift mutation to the TREX1 gene. This genetically inherited condition affects the retina and the white matter of the central nervous system, resulting in vision loss, lacunar strokes and ultimately dementia. Symptoms commonly begin in the early to mid-forties, and treatments currently aim to manage or alleviate the symptoms rather than treating the underlying cause. The overall prognosis is poor, and death can sometimes occur within 10 years of the first symptoms appearing.

AD-RVCL (CRV) Acronym

Autosomal Dominance (genetics) means only one copy of the gene is necessary for the symptoms to manifest themselves.

Retinal Vasculopathy means a disorder that is associated with a disease of the blood vessels in the retina.

Cerebral means having to do with the brain.

Leukodystrophy means a degeneration of the white matter of the brain.

Pathogenesis

The main pathologic process centers on small blood vessels that prematurely “drop out” and disappear. The retina of the eye and white matter of the brain are the most sensitive to this pathologic process. Over a five to ten-year period, this vasculopathy (blood vessel pathology) results in vision loss and destructive brain lesions with neurologic deficits and death.

Most recently, AD-RVCL (CRV) has been renamed. The new name is CHARIOT which stands for Cerebral Hereditary Angiopathy with vascular Retinopathy and Impaired Organ function caused by TREX1 mutations.

Treatment

Currently, there is no therapy to prevent the blood vessel deterioration.

About TREX1

The official name of the TREX1 gene is “three prime repair exonuclease 1.” The normal function of the TREX1 gene is to provide instructions for making the 3-prime repair exonuclease 1 enzyme. This enzyme is a DNA exonuclease, which means it trims molecules of DNA by removing DNA building blocks (nucleotides) from the ends of the molecules. In this way, it breaks down unneeded DNA molecules or fragments that may be generated during genetic material in preparation for cell division, DNA repair, cell death, and other processes.

Changes (mutations) to the TREX1 gene can result in a range of conditions one of which is AD-RVCL. The mutations to the TREX1 gene are believed to prevent the production of the 3-prime repair exonuclease 1 enzyme. Researchers suggest that the absence of this enzyme may result in an accumulation of unneeded DNA and RNA in cells. These DNA and RNA molecules may be mistaken by cells for those of viral invaders, triggering immune system reactions that result in the symptoms of AD-RVCL.

Mutations in the TREX1 gene have also been identified in people with other disorders involving the immune system. These disorders include a chronic inflammatory disease called systemic lupus erythematosus (SLE), including a rare form of SLE called chilblain lupus that mainly affects the skin.

The TREX1 gene is located on chromosome 3: base pairs 48,465,519 to 48,467,644

The immune system.

- The immune system is composed of white blood cells or leukocytes.

- There are 5 different types of leukocytes.

- Combined, the 5 different leukocytes represent the 2 types of immune systems (The general or innate immune system and the adaptive or acquired immune system).

- The adaptive immune system is composed of two types of cells (B-cells which release antibodies and T-cells which destroy abnormal and cancerous cells).

How the immune system becomes part of the condition.

During mitosis, tiny fragments of “scrap” single strand DNA naturally occur inside the cell. Enzymes find and destroy the “scrap” DNA. The TREX1 gene provides the information necessary to create the enzyme that destroys this single strand “scrap” DNA. A mutation in the TREX1 gene causes the enzyme that would destroy the single strand DNA to be less than completely effective. The less than completely effective nature of the enzyme allows “scrap” single strand DNA to build up in the cell. The buildup of “scrap” single strand DNA alerts the immune system that the cell is abnormal.

The abnormality of the cells with the high concentration of “scrap” DNA triggers a T-cell response and the abnormal cells are destroyed. Because the TREX1 gene is identical in all of the cells in the body the ineffective enzyme allows the accumulation of “scrap” single strand DNA in all of the cells in the body. Eventually, the immune system has destroyed enough of the cells in the walls of the blood vessels that the capillaries burst open. The capillary bursting happens throughout the body but is most recognizable when it happens in the eyes and brain because these are the two places where capillary bursting has the most pronounced effect.

Characteristics of AD-RVCL

- No recognizable symptoms until after age 40.

- No environmental toxins have been found to be attributable to the condition.

- The condition is primarily localized to the brain and eyes.

- Optically correctable, but continuous, deterioration of visual acuity due to extensive multifocal microvascular abnormalities and retinal neovascularization leading, ultimately, to a loss of vision.

- Elevated levels of alkaline phosphatase.

- Subtle vascular changes in the retina resembling telangiectasia (spider veins) in the parafovea circulation.

- Bilateral capillary occlusions involving the perifovea vessels as well as other isolated foci of occlusion in the posterior pole of the retina.

- Headaches due to papilledema.

- Mental confusion, loss of cognitive function, loss of memory, slowing of speech and hemiparesis due to “firm masses” and white, granular, firm lesions in the brain.

- Jacksonian seizures and grand mal seizure disorder.

- Progressive neurologic deterioration unresponsive to systemic corticosteroid therapy.

- Discrete, often confluent, foci of coagulation necrosis in the cerebral white matter with intermittent findings of fine calcium deposition within the necrotic foci.

- Vasculopathic changes involving both arteries and veins of medium and small caliber present in the cerebral white matter.

- Fibroid necrosis of vessel walls with extravasation of fibrinoid material into adjacent parenchyma present in both necrotic and non-necrotic tissue.

- Obliterative fibrosis in all the layers of many vessel walls.

- Parivascular, adventitial fibrosis with limited intimal thickening.

Conditions with similar symptoms that AD-RVCL can be misdiagnosed as:

- Brain tumors

- Diabetes

- Macular degeneration

- Telangiectasia (Spider veins)

- Hemiparesis (Stroke)

- Glaucoma

- Hypertension (high blood pressure)

- Systemic Lupus Erythematosus (SLE (same original pathogenic gene, but definitely a different disease because of a different mutation in TREX1))

- Polyarteritis nodosa

- Granulomatosis with polyangiitis

- Behçet's disease

- Lymphomatoid granulomatosis

- Vasculitis

Clinical Associations

- Raynaud's phenomenon

- Anemia

- Hypertension

- Normocytic anemia

- Normochromic anemia

- Gastrointestinal bleeding or telangiectasias

- Elevated alkaline phosphatase

Definitions

- Coagulation necrosis

- Endothelium

- Fibrinoid

- Fibrinoid necrosis

- Frameshift mutation

- Hemiparesis

- Jacksonian seizure

- Necrotic

- Necrosis

- Papilledema

- Perivascular

- Retinopathy

- Telangiectasia

- Vasculopathy

- Vascular

What AD-RVCL is not:

- Infection

- Cancer

- Diabetes

- Glaucoma

- Hypertension

- A neurological disorder

- Muscular dystrophy

- Systemic Lupus Erythematosis (SLE)

- Vasculitis

Things that have been tried but turned out to be ineffective or even make things worse:

- Antibiotics

- Steroids

- X-Ray therapy

- Immunosuppression

History of AD-RVCL (CRV)

- 1985 – 1988: CRV (Cerebral Retinal Vasculopathy) was discovered by John P. Atkinson, MD at Washington University School of Medicine in St. Louis, MO

- 1988: 10 families worldwide were identified as having CRV

- 1991: Related disease reported, HERNS (Hereditary Endiotheliopathy with Retinopathy, Nephropathy and Stroke – UCLA

- 1998: Related disease reported, HRV (Hereditary Retinal Vasculopathy) – Leiden University, Netherlands

- 2001: Localized to Chromosome 3.

- 2007: The specific genetic defect in all of these families was discovered in a single gene called TREX1

- 2008: Name changed to AD-RVCL Autosomal Dominant-Retinal Vasculopathy with Cerebral Leukodystrophy

- 2009: Testing for the disease available to persons 21 and older

- 2011: 20 families worldwide were identified as having CRV

- 2012: Obtained mouse models for further research and to test therapeutic agents

The median age at diagnosis is 38 years. Women are at higher risk for developing breast cancer.