PAEDIATRIC RESPIRATORY REVIEWS (2001) 2, 365–371 doi:10.1053/prrv.2001.0173, available online at http://www.idealibrary.com on RECENT ADVANCES Skeletal dysplasias and their effect on the respiratory system P. J. Mogayzel and C. L. Marcus Eudowood Division of Pediatric Respiratory Sciences, The Johns Hopkins School of Medicine, Baltimore, MD, USA Summary Children with skeletal dysplasia frequently have pulmonary disease which can be life threatening. These pulmonary problems are due to multiple aetiologies in- cluding thoracic and craniofacial anomalies predisposing to restrictive lung disease, upper airway obstruction and central apnoea. Recognition of pulmonary disease and early in- tervention improves the survival and quality of life for these children. C  2001 Harcourt Publishers Ltd KEYWORDS achondroplasia, central apnoea, cervicomedullary decompression, mucopolysaccharidoses, obstructive sleep apnoea syndrome, osteogenesis imperfecta, skeletal dysplasia, thoracic deformity, tonsillectomy and adenoidectomy INTRODUCTION Skeletal dysplasias predispose both children and adults to significant pulmonary problems. Thoracic deformities create restrictive lung disease via abnormal chest wall me- chanics and lung hypoplasia. In addition, both clinically sig- nificant central apnoea and upper airway obstruction oc- cur in individuals with various skeletal dysplasias. Several rare skeletal dysplasias cause severe respiratory compro- mise and death in the neonatal period. The timely diagno- sis and treatment of respiratory problems in less severely affected infants and children can promote better growth and cognitive development. Early intervention can also prevent more serious complications including chronic hy- poxaemia, cardiac compromise, respiratory failure and death. Correspondence to: Peter J. Mogayzel, Jr., MD, PhD, Johns Hopkins Hospital, Eudowood Division of Respiratory Sciences, 600 North Wolfe Street, Park 316, Baltimore, Maryland 21287- 2533, USA. Tel: +1 410 614 5637, Fax: +1 410 955 1030. e-mail: mogayzel@mail.jhmi.edu AETIOLOGY Thoracic deformities and restrictive lung disease Skeletal dysplasias often have characteristic thoracic de- formities. Severe chest wall abnormalities can create a small thorax leading to respiratory insufficiency, usually beginning in infancy. Most of these disorders are rare and associated with death in the neonatal period (Table 1). The aetiology of the pulmonary pathology seen in these syndromes is multifactorial and includes abnormal chest wall mechanics, lung hypoplasia and poor lung compliance. Abnormal chest wall growth and progressive kyphoscoliosis associated with some skeletal dysplasias causes significant respiratory complications. 1,2 Restrictive lung disease develops over time in patients with progres- sive kyphoscoliosis as their chest wall mechanics worsen. Restrictive lung disease is characterised by a pattern of rapid, shallow breathing associated with a low pulmonary reserve. Children with low pulmonary reserve often have respiratory problems during sleep when minute venti- lation normally decreases. In addition, restrictive lung 1526–0542/01/040365 + 07 $35.00/0 C  2001 Harcourt Publishers Ltd