A form of short-limb dwarfism associated with facial dysmorphism and frequent respiratory distress due to airway obstruction and chest anomalies.
Camptomelic Syndrome; Camptomelic Dwarfism.
The estimated prevalence is about 1:40,000-200,000 live births.
Familial autosomal dominant inheritance has been described, but most cases appear as de novo mutations. The defect is caused by mutations in the SOX9 (SRY-BOX 9) gene located on chromosome 17q24.3.
Based on the clinical and radiologic features. Molecular genetic testing is used to confirm the diagnosis.
The skeletal dysplasia is characterized by short-limb dwarfism with prenatal onset and shortening and bowing of femora and tibiae with shortened fibulae, progressive cervicothoracic kyphoscoliosis, spinal dysraphism, hypoplastic, absent or poor ossification of cervical and thoracic vertebrae, small and narrow thoracic cavity, 11 pairs of ribs, hypoplastic scapulae, small iliac wings, dislocation of the hips, talipes equinovarus, and generalized hypotonia. Cervical vertebral hypoplasia or malformation may lead to neurologic signs of cord compression. Facial dysmorphism may include macrocephaly, large anterior fontanelle, conductive and sensorineural hearing loss, hypertelorism, mild midface hypoplasia, flat nasal bridge, anteverted nares, Pierre Robin sequence with micro-/retrognathia, cleft palate, glossoptosis, and laryngo- and/or tracheobronchomalacia secondary to anomalous cartilage development. Mental retardation has been found in approximately 84% of patients in one study, while other reports describe normal intelligence in the majority of patients. Congenital heart defects (atrial or ventricular septal defects, aortic stenosis, tetralogy of Fallot) are reported in about one-third of patients. Hydronephrosis has been found in about one-third of patients. Respiratory failure is due to multilevel airway obstruction, laryngo- and tracheobronchomalacia, and hypoplastic thoracic cage and may result in early neonatal death, or require intubation and/or tracheostomy shortly after birth. Even with a tracheotomy, some patients continue to have respiratory failure because of distal airway collapse and obstruction in combination with restrictive changes of the thoracic cage. A male-to-female sex reversal occurs in two-thirds of male patients with 46,XY karyotype and may lead to ambiguous genitalia or complete sex-reversal with normal female sexual differentiation.
Precautions before anesthesia
Obviously, airway anomalies are the main focus of the anesthetic assessment and should also include cervical spine examination. Preoperative blood work should include a complete blood count, serum electrolytes, creatinine, and urea in case of bilateral hydronephrosis. Thorough cardiac evaluation is recommended due to the high rate of congenital cardiac defects and should include echocardiography and an electrocardiogram. Postoperative mechanical ventilation is most likely required and arrangements for it should be made beforehand.
Airway management has been described as straightforward with a Cormack-Lehane Grade I view on direct laryngoscopy in some cases. However, ...