Atypical glycine encephalopathy is a rare genetic disorder that affects the brain. It is caused by a mutation in the GLDC gene, which is responsible for producing an enzyme called glycine decarboxylase. This enzyme is necessary for the metabolism ...

Atypical Hemolytic Uremic Syndrome (aHUS) is a rare, life-threatening disorder that affects the kidneys, blood, and other organs. It is caused by abnormal activity of the complement system, a part of the immune system. Symptoms of aHUS include ane...

Atypical hemolytic uremic syndrome with anti-factor H antibodies (aHUS-AFH) is a rare, life-threatening disorder caused by an abnormal immune response. It is characterized by the formation of antibodies against the protein factor H, which is invol...

Atypical hypotonia-cystinuria syndrome is a rare genetic disorder characterized by hypotonia (low muscle tone), cystinuria (an inherited disorder of amino acid metabolism), and other symptoms. Symptoms may include delayed development, intellectual...

Atypical juvenile parkinsonism is a rare neurological disorder that affects children and young adults. It is characterized by symptoms similar to those of Parkinson's disease, including tremors, slow movement, and difficulty with balance and coord...

Atypical lichen myxedematosus is a rare autoimmune disorder that affects the skin. It is characterized by the formation of thick, waxy patches on the skin, usually on the face, neck, and upper chest. These patches can be itchy and may cause pain o...

Atypical Meigs syndrome is a rare condition characterized by the presence of a benign ovarian tumor (fibroma) and ascites (fluid accumulation in the abdomen). It is usually associated with pleural effusions (fluid accumulation in the chest cavity)...

Atypical Norrie disease due to Xp11.3 microdeletion is a rare genetic disorder caused by a deletion of a small piece of genetic material on the X chromosome. It is characterized by severe vision loss, intellectual disability, and hearing loss. It ...

Atypical pantothenate kinase-associated neurodegeneration (PKAN) is a rare, inherited neurological disorder caused by mutations in the PANK2 gene. It is characterized by progressive dystonia (involuntary muscle contractions) and other neurological...

Atypical papilloma of the choroid plexus is a rare, benign tumor that develops in the choroid plexus, a network of blood vessels and nerve fibers in the brain. It is usually found in the lateral ventricles, the two large cavities in the brain. Sym...

Atypical progressive supranuclear palsy (aPSP) is a rare neurological disorder that affects movement, balance, and other functions. It is a form of progressive supranuclear palsy (PSP), a group of disorders that cause problems with movement, balan...

Atypical teratoid rhabdoid tumor (AT/RT) is a rare, aggressive type of cancer that usually affects children under the age of three. It is a tumor of the central nervous system, most commonly found in the brain and spinal cord. AT/RT is a fast-grow...

Atypical Timothy syndrome is a rare genetic disorder that affects the heart, nervous system, and other parts of the body. It is caused by a mutation in the CACNA1C gene, which is responsible for the production of a protein that helps regulate the ...

Atypical Werner syndrome is a rare genetic disorder that is characterized by premature aging. It is caused by a mutation in the WRN gene, which is responsible for producing a protein that helps maintain the stability of chromosomes. Symptoms of At...

Audiogenic seizures are seizures that are triggered by sound. They are most commonly seen in certain breeds of dogs, such as Beagles, Dachshunds, and Cocker Spaniels. Symptoms of audiogenic seizures can include trembling, salivation, and loss of c...

Auditory neuropathy-optic atrophy syndrome (ANOS) is a rare genetic disorder that affects the auditory and visual systems. It is characterized by hearing loss, optic atrophy (degeneration of the optic nerve), and other neurological symptoms. The h...

Auditory Processing Disorder (APD) is a complex problem. The term is used by many people, in very different ways. There is research underway to help understand this disorder. There also is research to investigate therapies that will help individua...