Pterygium Syndrome

At a glance

Association of multiple pterygia with facial anomalies, and orthopedic and genitourinary malformations. It is characterized by short stature, webbing of the neck, antecubital, digital, popliteal, and intercrural areas. Joint contractures, vertebral fusion defects, and rocker-bottom feet are usually associated.

Synonyms

Multiple Pterygium Syndrome; Escobar Syndrome; Pterygium Universale; Pterygium Colli Syndrome.

History

First described in 1978 by V. Escobar, an American physician.

Incidence

Unknown; however, case reports only.

Genetic inheritance

Autosomal recessive inheritance in many cases, autosomal dominant determination in others. Some cases have been reported as sporadic occurrence.

Pathophysiology

The pterygium syndrome is caused by homozygous or compound heterozygous mutation in the CHRNG gene on chromosome 2q37.1, which encodes the gamma subunit of the acetylcholine receptor (AChR). This subunit is expressed before the 33rd week of gestation in humans but is replaced by the epsilon subunit in the late fetal and perinatal period, thereby forming the adult AChR. It is thought that the transient inactivation of the neuromuscular end plate leads to the dysmorphic features and account for the absence of myasthenic symptoms later in life.

Diagnosis

On the association of multiple pterygia, syndactyly, cleft palate, and micrognathia.

Clinical aspects

Facial anomalies are frequent (severe micro- or retrognathia, ptosis, telecanthus, microcephaly, spoonlike shape of the tongue [lingua cochlearis], cleft hard palate, ankyloglossia, deafness), normal intelligence, cardiac defect can be present, muscle weakness, myopathy, multiple orthopedic modifications (scoliosis, symphalangy, webbed neck, webbing of joints, talipes varus/valgus, syndactyly of fingers, short stature, vertebral segmentation abnormality and fusion), genitourinary tract malformation, and occasional diaphragmatic hernia. Joint contractures and rocker-bottom feet are frequently seen.

Precautions before anesthesia

Evaluate carefully the airway (clinical, radiograph, and even endoscopy) because of facial anomalies and webbed neck. Evaluate pulmonary function (chest radiograph, pulmonary function test, arterial blood gas analysis) because of the high rate of restrictive lung disease that is observed. Search for congenital heart defect or cardiomyopathy (clinical, echography). Laboratory test should include creatine phosphokinase.

Anesthetic considerations

There is a high rate of tracheal intubation difficulties because of anatomical status; laryngeal mask airways have been successfully used. Fiberoptic intubation can be useful but may be difficult. Caution with intraoperative patient positioning (pterygia, fixed joints). Close perioperative respiratory observation in case of respiratory insufficiency. Perimedullar anesthesia is not contraindicated but could be difficult to perform because of vertebral fusion and kyphoscoliosis. Check for spina bifida occulta. In the presence of cardiac defects, the anesthetic management should be tailored accordingly.

Pharmacological implications

Antibiotic prophylaxis in case of cardiac ...