Otopalatodigital (OPD) Syndrome Type I

At a glance

Rare congenital association characterized by coarse facial features (hypertelorism, prominent supraorbital ridges, abnormal pinnae, broad nasal bridge with small nose and mouth, and downward-slanting palpebral fissures), posterior cleft palate, conduction deafness, and broad distal digits with short nails.

Synonym

Taybi Syndrome.

Genetic inheritance

X-linked transmission with intermediate expression in females and complete expression in males.

Incidence

Rare, fewer than 100 cases described.

Pathophysiology

This syndrome is caused by gain-of-function mutations in the gene encoding filamin A on chromosome Xq28. Filamin A regulates the reorganization (crosslinking) of the actin cytoskeleton by interacting with integrins, transmembrane receptor complexes, and second messengers.

Diagnosis

Based on clinical aspect and radiography; female carriers present mild clinical expression (short nails, clinodactyly of toes, radiograph of anomalies in limbs and skull). A secondary ossification center at the base of the second metacarpal and metatarsal is characteristic.

Clinical aspects

Small stature (<10th percentile for age); mild mental deficiency with moderate conductive deafness. Facial bone hypoplasia with hypertelorism, small nose and mouth are present. The presence of a broad nasal root gives the affected individual a pugilistic appearance. Partial anodontia; cleft soft palate. Thickened base of skull and frontal bone with frontal and occipital prominence; failure of fusion of the posterior aspects of the spine. Absent frontal and sphenoid sinuses. Pectus excavatum. Brachydactyly with cone-shaped epiphyses, cutaneous syndactyly, flattened tip of thumbs, splayed “frog” feet with a short hallux and a large gap between the first and second toes, and lateral curvature of the toes (clinodactyly on the fifth fingers and broad big toes); short nails, clinodactyly, limited elbow extension with dislocation of radial head. Small iliac crests.

Precautions before anesthesia

Check teeth for caries and fragility. It is recommended to obtain a radiograph of the spine to rule out cervical instability (especially C1-C2 atlanto-axial junction) and/or risk of brainstem compression during head flexion or extension. Severe pectus excavatum may result in restrictive pulmonary disease. Facial bone hypoplasia with small nose places the patient at risk for obstructive sleep apnea.

Anesthetic considerations

Possible difficult direct laryngoscopy and tracheal intubation. Postoperative brainstem compression secondary to thickened base of the skull has been reported. Potentially difficult intravenous access.

Pharmacological implications

No specific implications.

Other conditions to be considered

The similarity of the otopalatodigital spectrum disorders indicates a common biochemical and/or genetic etiology in their pathogenesis.

• ☞Melnick-Needles Syndrome: Genetic disorder characterized by abnormal bone development. Lethal male form is a genetic disorder characterized by abnormal bone development. ...