Kousseff-Nichols Syndrome

At a glance

Often neonatal lethal syndrome with facial malformations and generalized myopathy with a high risk of malignant hyperthermia. This medical condition is classified in the list of hyperpyrexia disorders.

Synonym

Noonan-Like Contracture Myopathy Hyperpyrexia Syndrome.

Incidence

Extremely rare syndrome without a known incidence or prevalence.

Genetic inheritance

It is most likely inherited as an autosomal recessive inheritance.

Clinical aspects

Patients present with short stature and myopathy. Clinical features may involve head and neck (webbed short neck with excess nuchal skin, expressionless face, epicanthic folds, down-slanted fissures, micrognathia, high-vaulted, narrow palate, low-set, posterior ears), and the musculoskeletal system (restricted joint mobility, scoliosis, webbing of joints, symphalangy, abnormal rib structure, abnormal scapula position, terminal hypoplasia of fingers, and camptodactyly). Absent nipples, abnormal scarring, and abnormal dental position can be associated. Death is frequent in neonatal period secondary to respiratory distress.

Anesthetic considerations

There is no literature available. Based on the information available from the Noonan Syndrome, this Noonan-like medical condition should help guide the anesthesia plan. Proper evaluation of the airway must be conducted in preparation for the laryngoscopy and tracheal intubation must be expected to present challenges. It is recommended with the facial malformations to maintain spontaneous ventilation until the airway has been secured and ventilation of the lungs is confirmed. The availability of proper sizes laryngeal mask airway (LMA) must always be present in case of failure to control the airway. Careful intraoperative positioning must be used in view of the fragile skeletal conditions. Evaluate the respiratory function because of the skeletal deformations and myopathy. Postoperative ventilatory support may be necessary depending on the importance of the surgical procedure. Because of the association between generalized myopathy and the possibility of malignant hyperthermia, avoidance of all potential triggering agents must be avoided. Volatile agents and succinylcholine therefore are contraindicated. Dantrolene should be easily available and in proper quantity for the weight of the patient. In case of a malignant hyperthermic reaction, postoperative critical care and monitoring will be required.

Pharmacological Implications

The higher risk of malignant hyperthermia associated with this disorder requires that triggering anesthetic agents be avoided. It will be necessary to ensure the accessibility of proper quantity of dantrolene for the weight of the patient.

References