ALPS: Autoimmune lymphoproliferative syndrome.
ALPS is caused by genetic mutation most often in the FAS gene. It is characterized by non-malignant proliferations of lymphoid tissue resulting in enlargement of lymph nodes and liver and sometimes the spleen- which can result in hypersplenism- a condition in which a large spleen too actively filters the blood, lowering circulating numbers of cells. The condition usually manifests in the first year of life, waxes and wanes, then usually spontaneously improves in the second decade of life. ALPS can be complicated by autoimmune disorders usually affecting mostly the blood cells. The condition is associated with an increased lifetime increased risk of both Hodgkin’s and non-Hodgkin’s lymphoma. Severe manifestations of the disease may respond to cortisone drugs and other immune suppressive medications. Splenectomy does not cure the condition and results in an increased risk of infections. Bone marrow transplant can be curative but is usually reserved for those with lymphomas or severe subtypes of the disease caused by unusual mutations.
- Aicardi syndrome
Aicardi syndrome: A genetic disorder characterized by the partial or complete agenesis of the corpus callosum (the structure that links the 2 hemispheres of the brain), infantile spasms (a characteristic form of childhood seizures), mental retardation, and an ocular (eye) abnormality called chorioretinal lacunae in which there are lacunae (holes) in the retina of the […]
AHD: Abbreviation for alveolar hydatid disease; American Hospital Directory; and atherosclerotic heart disease.
- Alstrom syndrome
Alstrom syndrome: A progressive genetic disorder characterized by obesity, deafness, and visual problems in childhood and diabetes with insulin resistance (type 2 diabetes) and kidney failure in adulthood. Individuals with Alstrom syndrome have been identified in over 20 countries. Although the syndrome is generally rare, it is unusually frequent among Acadians, both those living in […]
- ALT (alanine aminotransferase)
ALT (alanine aminotransferase): An enzyme normally present in liver and heart cells that is released into the bloodstream when the liver or heart is damaged. The blood ALT levels are elevated with liver damage (for example, from viral hepatitis) or with an insult to the heart (for example, from a heart attack). Some medications can […]
- Alternating hemiplegia of childhood
Alternating hemiplegia of childhood: A rare neurological disorder with frequent temporary episodes of paralysis of one side of the body (hemiplegia) usually beginning before the age of 18 months. The eye movements, face, or limbs can be paralysed on either side of the body, but on only one side at a time. The cause is […]