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 ...

Alopecia antibody deficiency is an autoimmune disorder in which the body's immune system mistakenly attacks the hair follicles, resulting in hair loss. It is also known as alopecia areata. Symptoms of alopecia antibody deficiency include patchy ha...

Alopecia areata is an autoimmune disorder that causes patchy hair loss on the scalp, face, and sometimes other parts of the body. It is thought to be caused by the immune system mistakenly attacking the hair follicles, leading to hair loss. Alopec...

Alopecia totalis is a type of hair loss disorder that causes complete baldness of the scalp. It is an autoimmune disorder, meaning that the body's immune system mistakenly attacks the hair follicles, leading to hair loss. Alopecia totalis is a rar...

Alopecia universalis is a rare form of alopecia, an autoimmune disorder that causes complete hair loss on the scalp and body. It is the most severe form of alopecia, and it affects both men and women. People with alopecia universalis have no hair ...

Alopecia-contractures-dwarfism-intellectual disability syndrome is a rare genetic disorder characterized by alopecia (hair loss), contractures (stiffness of the joints), dwarfism, and intellectual disability. It is caused by a mutation in the gene...

Alopecia-epilepsy-pyorrhea-intellectual disability syndrome (AEPID) is a rare genetic disorder characterized by the presence of alopecia (hair loss), epilepsy, pyorrhea (gum disease), and intellectual disability. It is caused by a mutation in the ...

Alopecia-intellectual disability syndrome is a rare genetic disorder characterized by the absence of hair (alopecia) and intellectual disability. It is caused by a mutation in the gene encoding the protein filaggrin, which is involved in the forma...

Alopecia-intellectual disability-hypergonadotropic hypogonadism syndrome (AIDHH) is a rare genetic disorder characterized by alopecia (hair loss), intellectual disability, and hypergonadotropic hypogonadism (elevated levels of gonadotropins, hormo...

Alpers disease is a progressive neurologic disorder that begins during childhood and is complicated in many instances by serious liver disease. Symptoms include increased muscle tone with exaggerated reflexes (spasticity), seizures, and loss of co...

Alpers-Huttenlocher syndrome (AHS) is a rare, progressive neurological disorder that affects the brain and liver. It is characterized by seizures, developmental delay, and liver failure. It is caused by mutations in the POLG gene, which is respons...

Alpha delta granule deficiency is a rare genetic disorder characterized by a deficiency of alpha delta granules, which are specialized granules found in the cytoplasm of certain types of white blood cells. People with this disorder have an increas...

Tangier Disease is an inherited blood disorder involving decreased concentrations of fat compounds in the blood called high-density lipoproteins (sometimes called "good cholesterol"). Large amounts of these compounds may accumulate in certain orga...

What is alpha thalassemia? Alpha thalassemia is a blood disorder that reduces the production of normal hemoglobin. Hemoglobin is the protein in red blood cells that carries oxygen to cells throughout the body. What are the types of...

Alpha thalassemia is a genetic disorder that affects the production of hemoglobin, the protein in red blood cells that carries oxygen throughout the body. It is caused by a mutation in one or more of the four genes that control the production of a...

Alpha Thalassemia X-linked Intellectual Disability Syndrome (ATXID) is a rare genetic disorder caused by a mutation in the ATRX gene. It is characterized by intellectual disability, developmental delays, and alpha thalassemia, a type of anemia. Sy...

The Alpha-1 antitrypsin deficiency is a condition or disease that causes the body to not produce enough Alpha-1 antitryp...