Acrofacial Dysostosis Weyers Type

At a glance

A syndrome with postaxial polydactyly of the hands and feet, fusion of the fifth and sixth metatarsals and metacarpals, micrognathia with osseous cleft of the mandible, and dental anomalies. Cardiac defects (atrial or ventricular septal defects) are common.

Synonyms

Weyers Syndrome II; Weyers Acrodental Dysostosis; Curry-Hall Syndrome; Acrodental Dysostosis.

History

First described in 1952 by the German pediatrician and pedontologist Helmut Weyers (1920–1986).

Incidence

Unknown, but considered very rare.

Genetic inheritance

This type of acrofacial dystostosis has autosomal dominant inheritance. In its allelic variant, the Ellis-van Creveld Syndrome; however, inheritance is autosomal recessive. The defect is caused by mutations in the Ellis-van Creveld 2 (EVC2) gene, which has been mapped to chromosome 4p16.2. Both genders are equally affected.

Diagnosis

Based on the clinical findings, family history and genetic studies.

Clinical aspects

Slightly short stature (height usually around the 5th percentile), postaxial polydactyly Type A (hexadactyly) of the hands and feet, fusion of the fifth and sixth metatarsals and metacarpals, and mild brachydactyly. Other findings may include micrognathia with osseous clefts of the mandibular symphysis, small mouth with multiple labial frenula, and dental anomalies (hypodontia, conical shape of the permanent teeth, irregularly shaped, or absent incisors). Heart defects (mainly atrial or ventricular septal defects) can be found in over 70% of patients. Dysplastic and dystrophic finger- and toenails are common. The coincidental finding of a double epiglottis was reported in an adult male with this disorder.

Precautions before anesthesia

Airway management could be challenging, although the phenotype is quite variable and some of the features can be quite mild. Assess for cardiac defects and obtain an echocardiography as required.

Anesthetic considerations

If difficult airway management is a risk, then it is recommended to maintain spontaneous ventilation until the airway has been secured. Alternative airway management options should be immediately available (eg, supraglottic airway device, fiberoptic bronchoscope) and adherence to an established difficult airway algorithm is advised. A surgeon familiar with surgical airway management and the necessary equipment should easily be available in the operating room. Awake fiberoptic intubation should be considered. Because of the dental anomalies, extra care should be taken to avoid dental damage as a result of direct laryngoscopy. Depending on the extent of the limb anomalies, peripheral intravenous access could be difficult. Cardiac anomalies may require a specific and tailored anesthetic approach. Meticulous attention should be paid to avoid air bubbles in infusion-lines in patients with right-to-left shunts. Antibiotic prophylaxis for subacute bacterial endocarditis may be required.

Pharmacological implications

Nitrous oxide should be avoided in ...