There is a great deal of clinical heterogeneity in this group of ciliary dyskinesias. Developmental delays, cognitive impairment, truncal ataxia, breathing irregularities, and behavioral disorders are among the more common features. Hyperactivity and aggressiveness combined with dependency require constant vigilance and care. Postaxial polydactyly is a feature of some cases. Hypotonia is evident at birth. Liver failure and renal disease develop in many individuals. Neuroimaging of the midbrain-hindbrain area reveals agenesis or some degree of dysgenesis of the vermis with the 'molar tooth sign' in the isthmus region considered to be a diagnostic sign. The fourth ventricle is usually enlarged while the cerebellar hemispheres may be hypoplastic.
The facies features are said to be distinctive in older individuals. The face appears long with frontal prominence due to bitemporal narrowing, the nasal bridge and tip are prominent, the jaw is prominent, the lower lip protrudes, and the corners of the mouth are turned down.