Two main genes are involved: PHOX2B, observed in familial cases and frequently associated with other neurocristopathies (Ondine's and Hirschsprung's disease); and ALK, mostly in familial tumours.
Germline PHOX2B alterations were also recently discovered in neuroblastoma cases with CCHS and/or Hirschsprung disease, but a comprehensive survey for mutational frequency and functional consequence has not been performed.
The findings for HOXB5 and PHOX2B provide supportive evidence that genes regulating ENCC proliferation, migration and differentiation could be risk factors for HSCR.
Congenital central hypoventilation syndrome (CCHS), a unique disorder of respiratory control associated with Hirschsprung disease (HSCR) and tumors of neural crest origin, results from polyalanine repeat expansion mutations in the paired-like homeobox (PHOX)2B gene in more than 90% of cases, and alternative PHOX2B mutations in remaining cases.
Germline non-polyalanine repeat expansion mutations in PHOX2B (PHOX2B NPARM) predispose to peripheral neuroblastic tumors (PNT), frequently in association with other neurocristopathies: Hirschsprung disease (HSCR) or congenital central hypoventilation syndrome (CCHS).
We recently identified the paired-like homeobox 2B (PHOX2B, MIM 603851) gene as disease-causing in dysautonomic disorders including Congenital Central Hypoventilation Syndrome (CCHS), Hirschsprung disease (HSCR) and NB in various combinations.
We also report a germline PHOX2B mutation in one patient treated for Hirschsprung's disease who subsequently developed a multifocal neuroblastoma in infancy.
Using polymerase chain reaction amplification and direct sequencing, we screened PHOX2B coding regions and intron/exon boundaries for mutations and polymorphisms in 91 patients with HSCR and 71 ethnically matched controls.