Acrocephalopolysyndactyly Type III: Sakati-Nyhan-Tisdale Syndrome

At a glance

A disorder presenting with severe acrocephaly and distinctive leg defects (hypoplastic tibia, bowed femora, coxa valga), brachydactyly, duplication of the first toe, preaxial polydactyly, and congenital heart disease.

Synonyms

Acrocephalopolysyndactyly with Leg Hypoplasia; Sakati Syndrome.

History

First described in 1971 by Nadia Awni Sakati, a Syrian-Saudi pediatrician, William Leo Nyhan, and William K. Tisdale, both American pediatricians.

Genetic inheritance

Autosomal dominant inheritance is most likely. Advanced parental age might be a risk factor (although the mother of the index patient was only 34 years old).

Diagnosis

Clinical findings and radiographs of the skeleton will help establish the diagnosis.

Clinical aspects

Characterized by craniosynostosis of all sutures and acrocephaly, with a marked disproportion between the large calvarium and small face and radiological signs of longstanding increased intracranial pressure (ICP). Other facial findings include shallow orbits with hypotelorism and protrusion of the eyes, low-set, dysplastic ears with normal hearing. The maxilla appears shallow with a high-arched palate, and the mandibule is comparably large (although smaller than normal) and overbiting the maxilla. The arms and legs are short and the hands show brachy- and polydactyly and the feet poly- and syndactyly. There is bilateral coxa valga, with bowed femurs, hypoplastic tibias, and displacement of the fibulas posterior to the femurs. In addition, the index patient had some form of congenital heart disease with signs of left ventricular hypertrophy (no echocardiography available). Areas with alopecia and cutaneous atrophy of the scalp and linear submental scars resembling clefts have been described. The dermoglyphic patterns of the hands are abnormal. The nipples are widely spaced and similar to Carpenter Syndrome, the testes were undescended, and the genitalia hypoplastic. While achievement of developmental milestones was delayed in the index patient, his intelligence was considered normal (IQ of 90).

Precautions before anesthesia

Evaluate the head and neck anatomy with regards to difficult airway management (reduced size of nasopharynx, maxilla, mandible, anomalies of the palate). Request echocardiography for patients with suspected congenital cardiac lesions. As a rule of thumb, the incidence of increased ICP is 15% with one fused suture and 35% with two or more sutures affected. Positioning on the operating room table could be difficult and requires careful padding to avoid pressure sores.

Anesthetic considerations

Difficult airway management should be expected. Maintenance of spontaneous ventilation is recommended 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 ...