Autosomal dominant disorder characterized by a small, bell-shaped chest, laryngeal stenosis and iliac and pelvic dysplasia.
First described by the English physicians N. D. Barnes, D. Hall and S. Symons in 1969 in two patients (and their less affected mothers).
Unknown, but less than 10 cases have been described.
Autosomal dominant inheritance with variable penetrance has been suggested.
Constricted lungs in a restrictive chest wall as a result of the thoracic dysplasia give rise to respiratory distress in the newborn. In addition, laryngotracheal stenosis might cause upper airway obstruction with significantly increased work of breathing. The thoracic wall anomalies primarily affect the costochondral junctions and thus the growth of the ribs, which appear short, horizontal and fixed, leading to an extremely rigid chest cage that is small in all dimensions.
Radiologic and clinical features, family history.
The typical triad consists of small pelvis, laryngeal stenosis, and thoracic dysplasia with a small, bell-shaped chest (narrow upper part of the chest with slight flaring of the lower ribs). Affected individuals usually present with respiratory distress at birth, and tracheal intubation has been difficult in all the reported cases. Tracheostomy is usually indicated for long-term ventilation. Tracheostomy was performed as an emergency procedure in one patient at 5 weeks of age because the child could not be reintubated after a failed extubation trial. This child later underwent successful laryngotracheoplasty. Due to the small thorax and pelvis, the abdomen appears big and protuberant in babies with liver and spleen (despite being of normal size) palpable far below the costal margins. The pelvis is generally small with changes generally resemble those in achondroplasia with short, squared iliac bones, horizontal acetabula, and deep sciatic notches. Pulmonary function test results were reported for one patient. The total respiratory, the lung and the chest wall compliances were significantly reduced when compared to predicted values. Total respiratory, inspiratory, and expiratory resistances were all more than three times higher than normal. Functional residual capacity (FRC) was approximately one-third of predicted values, and the phase angle for thoraco-abdominal motion was more than twice the normal values, which is indicative of increased respiratory resistance and predominantly abdominal displacement during inspiratory breaths (diaphragmatic breathing). It was concluded that the lungs are not hypoplastic and that the reduced compliance is secondary to the thoracic volume reduction and stiff chest. The increased pulmonary resistance seems secondary to the low FRC. Lung collapse below the lower inflection point on the pressure-volume curve was thought to contribute to the collapse of the intrapulmonary airways. Thoracolumbar scoliosis is common. Long-term ...