Increased incidence of abnormal nasal cilia in patients with retinitis pigmentosa

Abstract

RETINITIS PIGMENTOSA (RP) is the name given to a group of inherited eye disorders of unknown aetiology, whose symptoms are loss of night vision and constriction of the field of vision. The conditions are progressive and eventually in some cases blindness occurs1. Although there are certain syndromes which include RP, for example, the Laurence–Moon–Biedl1, or Cockayne's syndrome2, in most cases the disease is considered to be localised to the eye. However, a high incidence of deafness has always been associated with RP1,4 and Massof and Finkle-stein (personal communication) have found that at least 15% of their cases have inner ear deafness not associated with pres-byacusis or acoustic trauma. As the outer limbs of photorecep-tors are modified cilia3 and the sensory epithelium of the inner ear is derived from ciliated epithelium, we wondered whether RP might be associated with a more general defect of ciliated structures. Accordingly we examined samples of nasal mucosa from 11 patients with RP and report here an increased incidence of cilia with abnormal axonemal microtubular structures, and also of compound cilia. Although our patient sample was small, it was heterogeneous and our findings may therefore apply to patients of different genetic type. If, as seems plausible, the ciliary abnormalities are related to the disease process in the eye, nasal mucosa would offer an accessible source of human material for the study of basic pathological processes in photoreceptors.