PHOX2B: a diagnostic cornerstone in neurocristopathies and neuroblastomas.

Paired-like homeobox 2B () is a gene essential in the development of the autonomic nervous system. mutations are associated with neurocristopathies-Hirschsprung disease (HSCR) and congenital central hypoventilation syndrome (CCHS)-and peripheral neuroblastic tumours. PHOXB2 plays an important role in the diagnostics of these conditions.Genotyping of a pathogenic variant is required to establish a diagnosis of CCHS. In HSCR patients, PHOX2B immunohistochemical staining has proven to be a valuable tool in identifying this disease. Furthermore, is a predisposition gene for neuroblastoma, in which PHOX2B immunohistochemical staining can be used as a highly sensitive and specific diagnostic marker. The utility of PHOX2B immunohistochemistry in pheochromocytoma and paraganglioma has also been studied but yields conflicting results.In this review, an overview is given of , its associated diseases and the usefulness of PHOX2B immunohistochemistry as a diagnostic tool.