A very rare genetic disease involving an enzyme (purine nucleoside phosphorylase - PNP) deficiency which causes a buildup of toxic metabolic products which in turn impairs the development of T-cells (part of the body's immune system). The condition is characterized primarily by frequent infections and various neurological symptoms.
A condition characterized by a tendency to bruise easily due to fragile blood vessels. A bruise may appear even if the person has not knowingly bumped that area. The condition is quite common but more prevalent in women than men. It is generally not considered as a serious condition as it is not associated with any other bleeding problems.
A rare inherited immunodeficiency disorder where the body's immune systm is unable to respond appropriately to certain viral infections (Epstein Barr virus).
Pycnodysostosis is perhaps best known as the diagnosis given retrospectively to the late 19th century French artist Henri de Toulouse-Lautrec (portrayed by Jose Ferrer in the 1952 film "Moulin Rouge"). Pycnodysostosis is a genetic (inherited) disease of the bone. Its pattern of inheritance follows the classic rules of genetics (see below). Pycnodysostosis consistently causes short stature. The height of adult males with the disease is less than 150 cm (59 inches, or 4 feet 1 inch). Adult females with pycnodysostosis are even shorter. Pycnodysostosis causes the bones to be abnormally dense (osteosclerosis); the last bones of the fingers (the distal phalanges) to be unusually short; and delays the normal closure of the connections (sutures)of the skull bones in infancy, so that the "soft spot" (the fontanel) on top of the head remains widely open. Pycnodysostosis causes brittle bones which easily break (fracture). The bones in the legs and feet tend to fracture. The jaw and collar bone (clavicles) are also particularly prone to fractures. The precise frequency of pycnodysostosis has never been determined. Pycnodysostosis can be classified in the large group of genetic diseases that are individually uncommon, but collectively important because of the sum of their numbers, their heavy impact upon affected individuals, and the equally heavy burden they place upon their families.
A very rare lethal syndrome characterized mainly by abnormal skeletal growth as well as abnormal bone calcification.
Pyle disease is listed as a "rare disease" by the Office of Rare Diseases (ORD) of the National Institutes of Health (NIH). This means that Pyle disease, or a subtype of Pyle disease, affects less than 200,000 people in the US population.
Pyoderma gangrenosum is a disease that causes tissue to become necrotic, causing deep ulcers that usually occur on the legs. When they occur, they can lead to chronic wounds. Ulcers usually initially look like small bug bites or papules, and they progress to larger ulcers. Though the wounds rarely lead to death, they can cause pain and scarring. The disease was identified in 1930. It affects approximately 1 person in 100,000 in the population. Though it can affect people of any age, it mostly affects people in their 40s and 50s.[1]
Pyogenic arthritis, pyoderma gangrenosum, and acne is listed as a "rare disease" by the Office of Rare Diseases (ORD) of the National Institutes of Health (NIH). This means that Pyogenic arthritis, pyoderma gangrenosum, and acne, or a subtype of Pyogenic arthritis, pyoderma gangrenosum, and acne, affects less than 200,000 people in the US population.
Pyomyositis, also known as tropical pyomyositis or myositis tropicans is a bacterial infection of the skeletal muscles which results in a pus-filled abscess. Pyomyositis is more common in tropical areas but can also occur in the temperate zones.
The PNPO gene provides instructions for producing an enzyme called pyridoxine 5′-phosphate oxidase. This enzyme is involved in the breakdown (metabolism) of vitamin B6. Specifically, it chemically modifies two forms of vitamin B6 derived from food (pyridoxine and pyridoxamine) to form pyridoxal 5′-phosphate (PLP). PLP is the active form of vitamin B6 and is necessary for many processes in the body, including protein metabolism and the production of chemicals that transmit signals in the brain (neurotransmitters). Pyridoxine 5′-phosphate oxidase is active (expressed) in cells throughout the body, with the highest amounts found in the liver.
At least 7 mutations in the PNPO gene have been found to cause pyridoxal 5′-phosphate-dependent epilepsy. Most of these mutations change one protein building block (amino acid) in the pyridoxine 5′-phosphate oxidase enzyme, impairing its normal function. The resulting enzyme cannot effectively metabolize pyridoxine and pyridoxamine to produce PLP. A shortage of PLP can disrupt the function of many other proteins and enzymes that need PLP in order to be effective. It is not clear how the lack of PLP affects the brain and leads to the seizures that are characteristic of this condition.
Pyridoxine deficiency (also known as B6 deficiency) is a paediatric disease due to a lack of pyridoxine (or vitamin B6). The disease presents with several key symptoms including seizures, irritability, cheilitis (inflammation of the lips), conjunctivitis and neurologic symptoms. It usually becomes noticeable within the first 12 months of life in infants with a lack of pyridoxine, a coenzyme responsible for numerous essential metabolic reactions in humans. It is rarely observed, even in undeveloped countries.[1][2]
Pyridoxine-dependent epilepsy is a condition that involves seizures beginning in infancy or, in some cases, before birth. Those affected typically experience prolonged seizures lasting several minutes (status epilepticus). These seizures involve muscle rigidity, convulsions, and loss of consciousness (tonic-clonic seizures). Additional features of pyridoxine-dependent epilepsy include low body temperature (hypothermia), poor muscle tone (dystonia) soon after birth, and irritability before a seizure episode. In rare instances, children with this condition do not have seizures until they are 1 to 3 years old. Anticonvulsant drugs, which are usually given to control seizures, are ineffective in people with pyridoxine-dependent epilepsy. Instead, people with this type of seizure are medically treated with large daily doses of pyridoxine (a type of vitamin B6 found in food). If left untreated, people with this condition can develop severe brain dysfunction (encephalopathy). Even though seizures can be controlled with pyridoxine, neurological problems such as developmental delay and learning disorders may still occur.
A metabolic error where a deficiency of an enzyme called dihydropyrimidine dehydrogenase prevents the normal metabolism of certain proteins. High levels of certain proteins are excreted in the urine. The enzyme is also needed the breakdown a chemotherapy drug called 5-flurouracil and its absence can result in a severe toxicity reaction.
A rare inherited condition where abnormal red blood cells are very sensitive to heat resulting in their destruction and hence, hemolytic anemia.
Pyrosis: The occurrence of chest pain which is consistent with gastro-oesophageal reflux. See free access online books about Pyrosis below. See detailed information below for a list of 0 causes of Pyrosis, including diseases and drug side effect causes.
Pyruvate carboxylase deficiency (PCD) is a rare non-sex linked (autosomal) disorder that results from an insufficient amount of the enzyme pyruvate carboxylase. This disorder is inherited as a recessive trait and it is known to be caused by more than one different mutation in the same gene (allelic variants).
A rare genetic disorder involving an enzyme (pyruvate decarboxylase) deficiency which results in symptoms such as failure to thrive, psychomotor retardation, small head, eye problems, increased blood ammonia levels and lactic acidosis which can result in infant death in severe cases.
Pyruvate dehydrogenase complex deficiency (PDCD) is a rare disorder of carbohydrate metabolism caused by a deficiency of one of the three enzymes in the pyruvate dehydrogenase complex (PDC). The age of onset and severity of disease symptoms vary widely. Individuals with PDCD symptom onset in the prenatal period or in infancy usually die in early childhood. Those who develop PDCD later in childhood may have neurological symptoms but usually survive into adulthood. Most individuals with PDCD have an abnormality in the PDHA1 gene located on the X chromosome. A smaller percentage of affected individuals have forms of the disorder that follow autosomal recessive inheritance.
An inherited deficiency of pyruvate kinase which causes varying degrees of hemolytic anemia.
An inherited deficiency of pyruvate kinase which causes varying degrees of hemolytic anemia.
Q fever is a disease caused by infection with Coxiella burnetii, a bacterium that affects humans and other animals. This organism is uncommon, but may be found in cattle, sheep, goats and other domestic mammals, including cats and dogs. The infection results from inhalation of a spore-like small cell variant, and from contact with the milk, urine, feces, vaginal mucus, or semen of infected animals. Rarely, the disease is tick borne. The incubation period is 9–40 days. Humans are vulnerable to Q fever, and infection can result from even a few organisms. The bacterium is an obligate intracellular pathogenic parasite.
Qazi Markouizos syndrome (medical condition): A very rare syndrome characterized mainly by abnormal bone development and muscle problems.
Quebec platelet disorder is listed as a "rare disease" by the Office of Rare Diseases (ORD) of the National Institutes of Health (NIH). This means that Quebec platelet disorder, or a subtype of Quebec platelet disorder, affects less than 200,000 people in the US population.
Quinquaud's decalvans folliculitis : A form of hair loss involving the gradual destruction and scarring of hair follicles which causes hair loss which spreads outwards from a central point.
Rabies is a viral disease that causes acute inflammation of the brain in humans and other warm-blooded animals. Early symptoms can include fever and tingling at the site of exposure. These symptoms are followed by one or more of the following symptoms: violent movements, uncontrolled excitement, fear of water, an inability to move parts of the body, confusion, and loss of consciousness. Once symptoms appear it nearly always results in death. The time period between contracting the disease and the start of symptoms is usually one to three months; however, this time period can vary from less than one week to more than one year. The time is dependent on the distance the virus must travel to reach the central nervous system.
A very rare genetic disorder involving severe insulin resistance which is where the body fails to be able to use insulin which is needed to control blood sugar levels.
Radiation maculopathy is a condition causing vision loss due to radiation therapy, often a delayed complication of treating <uveal melanoma or <head and neck cancers. It involves microvascular damage to the retina’s macula, leading to symptoms like macular edema, intraretinal hemorrhages, and capillary nonperfusion. While symptoms like visual distortion or blurring can occur, the most common initial finding is macular edema. Treatment primarily focuses on managing macular edema with <anti-VEGF agents and <steroids, but preventing the condition is the best strategy, and treatment outcomes are often modest or temporary.
Radioulnar synostosis type 1: A very rare syndrome characterized by fusion of the forearm bones (radius and ulna). The head of the radial bone is absent.
A very rare syndrome characterized by dislocation of the head of the radius (forearm bone) as well as fusion of the two forearm bones (radius and ulna).
Radioiodine-resistant (RAI-R) thyroid cancer, also known as radioiodine-refractory differentiated thyroid cancer (RAI-R DTC), occurs when thyroid cancer cells are unable to effectively uptake and utilize radioactive iodine in treatment. This resistance can lead to disease progression and potentially a poorer prognosis. RAI-R DTC is more common in older patients, those with advanced disease, and those with distant metastases.