Barnes Syndrome

Autosomal dominant disorder characterized by a small, bell-shaped thorax and laryngeal stenosis with iliac and pelvis dysplasia.

Thoraco-Laryngo-Pelvic Dysplasia.

Two families with two children each and one sporadic case have been described. The diagnosis was retrospectively suggested in a third family described with thoracopelvic dysostosis.

Classic mendelian autosomal dominant inheritance with variable penetrance has been suggested.

Small lungs and a restrictive chest wall as a result of the thoracic dysplasia give rise to respiratory distress in the newborn. In addition, laryngeal stenosis might cause upper airway obstruction with increased work of breathing.

Radiologic and clinical features, family history.

The typical triad consists of laryngeal stenosis, thoracic dysplasia with a small, bell-shaped chest wall, and a small pelvis. Affected individuals usually present with respiratory distress at birth, and tracheal intubation was difficult in all. Tracheostomy was 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. Because of the small thorax and pelvis, the abdomen appears big and protuberant in babies. Long-term outcome is not yet defined. Mortality is high; in fact, the oldest described individual who underwent thoracoplasty to increase the thoracic diameter in early childhood eventually died of cor pulmonale at 14 years of age. The children in the two families were delivered by cesarean section because of cephalopelvic disproportion (mother with small pelvis, who obviously suffered from a milder form of Barnes syndrome; however, tracheal intubation reportedly was difficult secondary to laryngeal stenosis).

Ideally, tracheal intubation is done in the delivery room or the operating room with an ear-nose-throat or pediatric surgeon present in case urgent tracheostomy is needed. Considering the available literature, assessing older children for the presence of pulmonary hypertension prior to intervention seems prudent.

High positive pressures might be necessary for adequate ventilation because of the restrictive chest physiology, especially in the younger child. Pulmonary hypertension, if present, may not be well tolerated, and the increased right ventricular afterload because of positive pressure ventilation leads to a higher risk of right ventricular failure. Avoid acidosis and hypercapnia to keep pulmonary vascular resistance as low as possible, which is of particular risk during induction with difficult face-mask ventilation and/or failed attempts of tracheal intubation.

In the presence of cor pulmonale, pulmonary vasoconstrictors should be avoided. If extubation is considered in patients with borderline respiratory function, a nerve stimulator should be used to prevent any residual paralysis.

Ellis-van Creveld Syndrome: Genetic form of short-limbed dwarfism.

Jeune Syndrome: Jeune and Barnes syndromes share the predominant feature of thoracic hypoplasia but are genetically distinct. In Jeune syndrome, chest wall hypoplasia tends to be more severe. In contrast, laryngeal stenosis is not a feature of the Jeune phenotype.

Short-Rib Polydactyly Syndrome Type II (Majewski Syndrome): Lethal entity characterized by median cleft lip, preaxial and postaxial polysyndactyly, short ribs and limbs, genital abnormalities, and anomalies of epiglottis and viscera. Other features include polycystic kidneys, transposition of the great vessels, and atretic lesions of the gastrointestinal and genitourinary systems.

Short-Rib Polydactyly Syndrome Type I (Saldino-Noonan Syndrome): Lethal condition of newborns characterized by hydropic appearance, postaxial polydactyly, severely shortened and flipper-like limbs, and striking metaphyseal dysplasia of tubular bones. The pelvis resembles that of Ellis-van Creveld syndrome and Jeune syndrome. As in type II (Majewski syndrome), polycystic kidneys, transposition of the great vessels, and atresic lesions of the gastrointestinal and genitourinary systems occur.

Short-Rib Polydactyly Syndrome Type III (Verman-Naumoff Syndrome): Lethal entity characterized by a short cranial base, bulging forehead, depressed nasal bridge, flat occiput.

Beemer-Langer Syndrome: Lethal entity presenting with hydrops, ascites, median cleft of the upper lip, narrow chest, and short, bowed limbs.

Other thoracic dysplasia syndromes, such as thanatophoric dwarfism, have been described rarely.