Unlike the case in CCHS, which is defined largely by polyalanine repeat expansion mutations that lead to expansion of the second polyalanine tract [8], [32], [33], germline PHOX2B mutations associated with neuroblastoma tend to be (i) missense alterations in highly conserved regions [4], [7], [33] or (ii) mutations that result in a frameshift, giving rise to an altered or truncated protein lacking the second polyalanine motif [5], [8], [33], [34]. The gene discussed is PHOX2B; the disease is neuroblastoma.