Sézary syndrome is an aggressive form of a type of blood cancer called cutaneous T-cell lymphoma. Cutaneous T-cell lymphomas occur when certain white blood cells, called T cells, become cancerous; these cancers characteristically affect the skin, cau READ MORE

Sheldon-Hall syndrome, also known as distal arthrogryposis type 2B, is a disorder characterized by joint deformities (contractures) that restrict movement in the hands and feet. The term "arthrogryposis" comes from the Greek words for joint (arthro-) READ MORE

Shingles (also known as herpes zoster) results from infection by the varicella zoster virus. This common virus causes chickenpox (also known as varicella), which is characterized by itchy spots on the skin that cover the whole body and usually occurs READ MORE

Short QT syndrome is a condition that can cause a disruption of the heart's normal rhythm (arrhythmia). In people with this condition, the heart (cardiac) muscle takes less time than usual to recharge between beats. The term "short QT" refers to a sp READ MORE

Short stature, hyperextensibility, hernia, ocular depression, Rieger anomaly, and teething delay, commonly known by the acronym SHORT syndrome, is a rare disorder that affects many parts of the body. Most people with SHORT syndrome are small at birth READ MORE

Short-chain acyl-CoA dehydrogenase (SCAD) deficiency is a condition that prevents the body from converting certain fats into energy, especially during periods without food (fasting). Signs and symptoms of SCAD deficiency may appear during infancy or READ MORE

Short/branched chain acyl-CoA dehydrogenase (SBCAD) deficiency (also known as 2-methylbutyryl-CoA dehydrogenase deficiency) is a rare disorder in which the body is unable to process proteins properly. Normally, the body breaks down proteins from food READ MORE

Shprintzen-Goldberg syndrome is a disorder that affects many parts of the body. Affected individuals have a combination of distinctive facial features and skeletal and neurological abnormalities. A common feature in people with Shprintzen-Goldberg sy READ MORE

Shwachman-Diamond syndrome is an inherited condition that affects many parts of the body, particularly the bone marrow, pancreas, and bones. The major function of bone marrow is to produce new blood cells. These include red blood cells, which carry o READ MORE

Sialidosis is a severe inherited disorder that affects many organs and tissues, including the nervous system. This disorder is divided into two types, which are distinguished by the age at which symptoms appear and the severity of features. Sialidosi READ MORE

Sialuria is a rare disorder that affects development. Infants with sialuria are often born with a yellow tint to the skin and the whites of the eyes (neonatal jaundice), an enlarged liver and spleen (hepatosplenomegaly), and unusually small red blood READ MORE

Sick sinus syndrome (also known as sinus node dysfunction) is a group of related heart conditions that can affect how the heart beats. "Sick sinus" refers to the sino-atrial (SA) node, which is an area of specialized cells in the heart that functions READ MORE