Primary ciliary dyskinesia (PCD) is a rare disorder with variable disease progression. To date, mutations in more than 20 different genes have been found. At present, PCD subtypes are described according to the ultrastructural defect on transmission electron microscopy (TEM) of the motile cilia. PCD with normal ultrastructure (NU) is rarely reported because it requires additional testing. Biallelic mutations in DNAH11 have been described as one cause of PCD with NU.

Key points: Children with neurocognitive impairment often present with chronic or recurrent respiratory problems. The respiratory problems have an important impact on quality of life and life expectancy. The underlying causes are multiple: risk of aspiration, insufficient cough, upper airway obstruction and progressive kyphoscoliosis. There is often a complex interplay between these known risk factors. The diagnostic and therapeutic approach should be multidisciplinary. Educational aims: To provide data on the prevalence of respiratory problems in children with disability and to increase awareness on this topic. To provide insight into the complex interplay of the underlying causes and risk factors for chronic lung infection and respiratory failure. To give an overview of the diagnostic approaches relevant in this context. To highlight possible therapeutic approaches. To touch on ethical considerations in this group of vulnerable and complex patients.