The primary cause of cystic fibrosis (CF), the most frequent fatal genetic
disease in Caucasians, is deletion of phenylalanine at position 508
(F508del), located in the first nucleotide-binding domain (NBD1) of the
CF transmembrane conductance regulator (CFTR) protein.
Salters-Nuﬃ eld Advanced Biology (SNAB) is much more
than just another A-level speciﬁ cation. It is a complete
course with its own distinctive philosophy. h e course is
supported by a comprehensive set of teaching, learning
and support materials which embrace a student centred
approach. SNAB combines the key concepts underpinning
biology today, combined with the opportunity to gain the
wider skills that biologists now need.
The guideline will not consider management of the fol-
lowing clinical presentations, although differential diagno-
sis for these conditions and bacterial rhinosinusitis will be
discussed: allergic rhinitis, eosinophilic nonallergic rhinitis,
vasomotor rhinitis, invasive fungal rhinosinusitis, allergic
fungal rhinosinusitis, vascular headaches, and migraines.
The cystic ®brosis transmembrane conductance regulator
(CFTR) gene shows a complex pattern of expression, with
temporal and spatial regulation that is not accounted for by
elements in the promoter. One approach to identifying the
regulatory elements forCFTRis the mapping of DNase I
hypersensitive sites (DHS) within the locus. We previously
identi®ed at least 12 clusters of DHS across theCFTRgene
andhere further evaluateDHS in introns 2, 3, 10, 16, 17a, 18,
20 and 21 to assess their functional importance in regulation
ofCFTRgene expression. ...