Dopamine beta-hydroxylase and its genetic variants in human health and disease.

Dopamine beta-hydroxylase (DβH) is an essential neurotransmitter-synthesizing enzyme that catalyzes the formation of norepinephrine (NE) from dopamine and has been extensively studied since its discovery in the 1950s. NE serves as a neurotransmitter in both the central and peripheral nervous systems and is the precursor to epinephrine synthesis in the brain and adrenal medulla. Alterations in noradrenergic signaling have been linked to both central nervous system and peripheral pathologies. DβH protein, which is found in circulation, can, therefore, be evaluated as a marker of norepinephrine function in a plethora of different disorders and diseases. In many of these diseases, DβH protein availability and activity are believed to contribute to disease presentation or select symptomology and are believed to be under strong genetic control. Alteration in the DβH protein by genetic polymorphisms may result in DβH becoming rate-limiting and directly contributing to lower NE and epinephrine levels and disease. With the completion of the human genome project and the advent of next-generation sequencing, new insights have been gained into the existence of naturally occurring DβH sequencing variants (genetic polymorphisms) in disease. Also, biophysical tools coupled with genetic sequences are illuminating structure-function relationships within the enzyme. In this review, we discuss the role of genetic variants in DβH and its role in health and disease.