CFTR and sinusitis: Sinus anatomy is also altered in CF patients, with ethmoid, maxillary, frontal, and sphenoid sinus hypoplasia or aplasia being exceptionally common.11 Whether sinus hypoplasia is a developmental consequence of loss of CFTR in utero or arises secondary to chronic sinusitis in childhood remains unknown.12, 13 Ethical concerns preclude studying CF sinus pathogenesis in the neonatal period, and only a few case reports are available to suggest when sinus disease might begin.11, 14–18