Andermann Syndrome

Familial syndrome characterized by agenesis of the corpus callosum, mental retardation, and progressive sensorimotor neuropathy.

Charlevoix Disease.

Originally described in French Canadians from Charlevoix County, Quebec, Canada. Traced back to a couple married in Quebec City in the 17th century. The incidence in the Saguenay and Lac St.-Jean region in the province of Quebec has been estimated as 1:2100 live births. The carrier rate is 1:23 inhabitants.

Autosomal recessive. The gene defect has been mapped to 15q13-q15.

Electromyography shows absence of sensory action potentials, slight reduction in motor nerve conduction velocity, and signs of denervation and reinnervation in the distal muscles of the lower extremities. Muscle biopsy shows angular fibers and atrophy. Overall pathologic picture is suggestive of a chronic demyelinating neuropathy.

Characteristic features include brachycephaly with a long, triangular, asymmetrical facies with hypoplastic maxilla, large mandibular angle, high arched palate, protruding tongue, and prominent chin with a long lip to chin distance. Bilateral blepharoptosis, hypertelorism, nystagmus, mild ophthalmoplegia, and abnormal visual evoked potentials have been described. The clinical course provides valuable clues to the diagnosis. CT scans show total or partial agenesis of the corpus callosum.

Unremarkable neonatal period followed by hypotonia and slowing of motor development, starting at age 4 to 6 months. Although some patients can walk, by age 10 to 13 years they are wheelchair-bound or bed-bound. Areflexia, paraparesis, psychosis, and seizures are observed. Other features include diffuse hypotonia, absence of deep tendon reflexes, flexion contractures in the metacarpophalangeal joints, low-set thumbs, pes equinovarus, hammertoe deformity, syndactyly of the toes, and sensory neuropathy in a glove and stocking distribution. Progressive scoliosis becomes apparent with older age and may lead to severely restrictive lung function. Moderate mental retardation with an IQ ranging from 45 to 60 in the majority of cases.

Evaluate pulmonary function (clinical, chest radiographs, CT, pulmonary function test, arterial blood gas analysis). Echocardiography should be performed if cor pulmonale and pulmonary hypertension are suspected. Assess the airway for difficult airway management. Evaluate neurologic function (clinical, full history, electroencephalogram, CT, MRI). Postoperative ventilatory support may be necessary and should be arranged beforehand.

No literature is available. Potentially difficult airway management in view of facial abnormalities. Spontaneous ventilation should be maintained until the airway is secured. Patients may not tolerate general anesthesia if respiratory function is severely reduced.

Because of increased sensitivity to muscle relaxants, avoid depolarizing muscle relaxants and use nondepolarizing agents cautiously under the control of a peripheral nerve stimulator. Consider interaction between anesthetic drugs and antiepileptic treatment.

Numerous syndromes are associated with agenesis of the corpus callosum. The following list is not all-inclusive.

Aicardi Syndrome: Combination of myoclonic seizures with characteristic EEG pattern, lacunar chorioretinopathy, and (complete or partial) agenesis of the corpus callosum is characteristic of this X-linked dominant inherited syndrome.

Schinzel Acrocallosal Syndrome: Very rare autosomal recessive, complex polymalformative disease with predominant neurologic and skeletal anomalies.

FG Syndrome: X-linked form of mental retardation associated with complete or partial agenesis of the corpus callosum and minor facial, skeletal, and gastrointestinal anomalies.

Cerebro-Reno-Digital Syndrome: Autosomal recessive inherited syndrome with corpus callosum agenesis, Dandy-Walker malformation, mental retardation, paraparesis or quadriparesis.

Dandy-Walker Malformation: Congenital anomaly of the cerebellum and fourth ventricle characterized by hypoplasia of the cerebellum and hydrocephalus resulting from cystic expansion of the fourth ventricle in the posterior fossa.

HARD Syndrome: Very rare, severe autosomal recessive, quickly lethal acronymic syndrome with major neurologic impairment. Common features include hydrocephalus, agyria, and retinal dysplasia. It is characterized by type II lissencephaly in association with retinal dysplasia, obstructive hydrocephalus, and agenesis of the corpus callosum. Affected infants typically have severe growth failure, severe microcephaly, seizures, microphthalmia, and cataracts. Some affected infants have an occipital encephalocele.

Opitz-Frias Syndrome: Genetic disorder characterized by craniofacial anomalies, ocular hypertelorism, cleft lip/palate, epicanthal folds, and a wide, flat nasal bridge. Affected males present cryptorchidism, bifid scrotum, and/or hypospadias. The most significant anomalies are the presence of cleft in the larynx and trachea, pulmonary hypoplasia, dysphagia, and respiratory obstruction. Hypoplasia or agenesis of the corpus callosum, kidney abnormalities, cardiac defects, and mental retardation have been reported.

Psaume Syndrome (Papillon Psaume Syndrome; OFD Type I): Congenital X-linked syndrome lethal for males, characterized by orofacial and digital defects associated with cardiac and renal anomalies.

Rubinstein-Taybi Syndrome: Rare syndrome characterized by craniofacial anomalies and complex multiple malformations, including cardiac, digestive, and respiratory.