Argininosuccinic aciduria (ASA) is an inherited metabolic disorder caused by a deficiency of the enzyme argininosuccinate lyase. This enzyme is responsible for breaking down the amino acid arginine, which is essential for normal growth and develop...

Ahumada-Del Castillo is a rare endocrine disorder affecting adult females, which is characterized by impairment in the function of the pituitary and hypothalamus glands. Symptoms may include the production of breast milk (lactation) not associated...

Argyria is a rare condition caused by long-term exposure to silver. It is characterized by a blue-gray discoloration of the skin, eyes, and mucous membranes. It is caused by the accumulation of silver particles in the body, which can be ingested t...

Holoprosencephaly (HPE) is the failure of the prosencephalon, or forebrain, to develop normally. The forebrain is a region of the brain in the fetus that develops into parts of the adult brain, including the cerebral cortex. Instead of the normal ...

Brachioplasty, more commonly known as an arm lift, is a surgical operation that: Reduces excessive, downward-drooping sagging skin The underlying supporting tissue that determines the contour of the upper arm is tightened ...

Chiari malformations are a group of complex brain abnormalities that affect the area in lower back of the skull where the brain and spinal cord connect. Chiari malformations are thought to be present at birth (congenital), although in many cases t...

Arnold-Chiari malformation type I is a congenital disorder in which the lower part of the brain, the cerebellum, is displaced downward into the upper spinal canal. This displacement can cause a variety of symptoms, including headaches, dizziness, ...

Arnold-Chiari malformation type II is a rare neurological disorder caused by a structural defect in the brain. It is characterized by a downward displacement of the cerebellar tonsils through the foramen magnum (the opening at the base of the skul...

Aromatase deficiency is a rare genetic disorder caused by a mutation in the CYP19A1 gene. This gene is responsible for producing the enzyme aromatase, which is responsible for converting androgens (male hormones) into estrogens (female hormones). ...

Aromatase excess syndrome is a rare genetic disorder caused by a mutation in the CYP19A1 gene. This gene encodes the enzyme aromatase, which is responsible for the production of the hormone estrogen. People with this disorder have an excess of est...

Aromatase inhibitors are a class of drugs that inhibit the enzyme aromatase, which is responsible for the conversion of androgens (male hormones) into estrogens (female hormones). By blocking this enzyme, aromatase inhibitors reduce the production...

Aromatic L-Amino Acid Decarboxylase Deficiency (AADC Deficiency) is a rare genetic disorder caused by a deficiency of the enzyme aromatic L-amino acid decarboxylase (AADC). This enzyme is responsible for the conversion of the amino acid L-dopa int...

Arrhinia-choanal atresia-microphthalmia syndrome is a rare genetic disorder characterized by the presence of two or more birth defects. It is characterized by choanal atresia (a blockage of the nasal passage), microphthalmia (abnormally small eyes...

A heart arrhythmia (uh-RITH-me-uh) is an irregular heartbeat. Heart rhythm probl...

A heart arrhythmia (uh-RITH-me-uh) is an irregular heartbeat. Heart rhythm problems (heart arrhythmias) occur when the electrical signals that coordinate the heart's beats don't work properly. The faulty signalling causes the heart to beat too fas...

What is arsenic? Arsenic is a grey-appearing chemical element (atomic number 33, symbol As in the periodic table) also termed a metalloid. Arsenic can exist in a metallic state in three forms (yellow, black, and gray; with gray predominati...

Arterial chemotherapy infusion of the liver and chemoembolization of the liver (transarterial chemoembolization or TACE) are similar procedures that are used for the treatment of cancers in the liver. In both procedures, chemotherapy is injected i...