Bloom syndrome is a rare genetic disorder characterized by short stature; increased sensitivity to light (photosensitivity); multiple small dilated blood vessels on the face (facial telangiectasia), often resembling a butterfly in shape; immune de...

Andersen disease belongs to a group of rare genetic disorders of glycogen metabolism, known as glycogen storage diseases. Glycogen is a complex carbohydrate that is converted into the simple sugar glucose for the body's use as energy. Glycogen sto...

Histidinemia is a rare hereditary metabolic disorder characterized by a deficiency of the enzyme histidase, which is necessary for the metabolism of the amino acid histidine. The concentration of histidine is elevated in the blood. Excessive amoun...

Hay-Wells syndrome, also known as ankyloblepharon-ectodermal dysplasia-clefting (AEC) syndrome, is a rare inherited disorder that belongs to a group of disorders known as the ectodermal dysplasias. Major characteristics of Hay-Wells syndrome inclu...

Prader-Willi syndrome (PWS) is a genetic multisystem disorder characterized during infancy by lethargy, diminished muscle tone (hypotonia), feeding difficulties, and poor weight gain. In childhood, features of this disorder include short stature, ...

Familial dysautonomia is a rare genetic disorder of the autonomic nervous system (ANS) that primarily affects people of Eastern European Jewish heritage. It is characterized by diminished sensitivity to pain, lack of overflow tearing in the eyes, ...