by Anne Marie Helmenstine, Ph.D. Updated June 13, 2014. Definition: A molecular orbital is an orbital or wavefunction of a molecule's electron. Electrons around a molecule can be associated with more than one atom and are often expressed as a combination of atomic orbitals.
Hereditary angioedema is a disorder characterized by recurrent episodes of severe swelling (angioedema). The most common areas of the body to develop swelling are the limbs, face, intestinal tract, and airway. Minor trauma or stress may trigger an attack, but swelling often occurs without a known trigger.
In the case of hereditary angioedema, there is a problem with the C1 inhibitor protein. The patient will have low blood levels of the protein C1-esterase inhibitor (C1-1NH protein). In this type of angioedema, episodes of angioedema will come and go over time.