Congenital cranial dysinnervation disorders (CCDD)

Abstract

Knowledge about hereditary eye diseases has been substantially increased by means of genetic testing during the last decade. This has resulted in a new classification of a number of disease patterns, which are characterised by non-progressive restrictive disorders of the oculomotor system, formerly classified as "congenital fibrosis syndromes". Based on the results of genetic testing, these ocular motility disorders are now referred to as "congenital cranial dysinnervation disorders" (CCDDs). They are caused by an impaired innervation of extraocular muscles because of a dysgenesis of the nuclei of the affected cranial nerves in the brainstem and pons and not by primary fibrosis of the extraocular muscles. In this review, congenital fibrosis of the extraocular muscles (CFEOM), Duane syndrome, horizontal gaze palsy with progressive scoliosis, congenital ptosis and Moebius syndrome are presented and basic principles of intracellular transport mechanisms and kinesins are discussed.