Anti-glomerular basement membrane disease (anti-GBM disease) is a rare autoimmune disorder in which the body's immune system mistakenly attacks the glomerular basement membrane (GBM), a thin layer of cells that lines the glomeruli in the kidneys. ...

Anti-HLA hyperimmunization is a process in which a person is exposed to high levels of antibodies against human leukocyte antigens (HLA). This process is used to induce tolerance to HLA antigens, which can be beneficial for people who need organ t...

Anti-p200 pemphigoid is a rare autoimmune skin disorder that is characterized by the formation of blisters and lesions on the skin. It is caused by the body's immune system attacking the proteins in the skin's basement membrane, which is the layer...

What is antiphospholipid syndrome? What are antiphospholipid syndrome symptoms and signs? The antiphospholipid syndrome is a disorder of the immune system that is characterized by excessive clotting of blood and/or certain complications of...

Antiphospholipid Syndrome (APS) is an autoimmune disorder characterized by the presence of antiphospholipid antibodies in the blood. These antibodies can cause recurrent blood clots, miscarriages, and other health problems. APS can affect any orga...

A personality disorder (PD) is a persistent pattern of thoughts, feelings, and behaviors that is significantly different from what is considered normal within the person's own culture. Personality disorders are grouped into clusters...

Antisynthetase Syndrome (AS) is a rare autoimmune disorder that affects the muscles and lungs. It is caused by an immune system that produces antibodies against certain aminoacyl-tRNA synthetases, which are enzymes that help the body make proteins...

Antithrombin deficiency is a rare inherited disorder that affects the body's ability to control blood clotting. People with this disorder have low levels of antithrombin, a protein that helps to prevent the formation of blood clots. Without enough...

Antley-Bixler Syndrome is a rare genetic disorder that is primarily characterized by distinctive malformations of the head and facial (craniofacial) area and additional skeletal abnormalities. For example, the disorder is typically associated with...

Antley-Bixler Syndrome (ABS) is a rare genetic disorder that affects the development of the bones, joints, and other organs. It is characterized by skeletal malformations, including craniosynostosis (premature fusion of the skull bones), midface h...

Antley-Bixler syndrome with genital anomaly and disorder of steroidogenesis (ABS-GAD) is a rare genetic disorder characterized by skeletal malformations, genital anomalies, and a disorder of steroidogenesis. Skeletal malformations can include cran...

Antley-Bixler syndrome without genital anomaly or disorder of steroidogenesis is a rare genetic disorder characterized by skeletal abnormalities, facial malformations, and respiratory and digestive problems. It is caused by mutations in the FGFR2 ...

Aortic arch anomaly-facial dysmorphism-intellectual disability syndrome is a rare genetic disorder characterized by a combination of aortic arch anomalies, facial dysmorphism, and intellectual disability. It is caused by a mutation in the gene enc...

Aortic arch interruption is a rare congenital heart defect in which the aortic arch, the main artery that carries oxygen-rich blood from the heart to the rest of the body, is interrupted or blocked. This can lead to a decrease in blood flow to the...

Introduction to aortic dissection The aorta is the large blood vessel that leads from the heart and carries blood to the rest of the body. It originates at the aortic valve at the outlet of the left ventricle of the heart and ascends withi...

What is aortic stenosis? Aortic stenosis is abnormal narrowing of the aortic valve. A number of conditions cause disease resulting in narrowing of the aortic valve. When the degree of narrowing becomes significant enough to impede the flow...