[MIM 166 350]

(Familial ectopic ossification)

Incidence < 1.106. Sporadic mutation or autosomal dominant transmission of a mutation of the GNAS gene (20q13.32). Appearance of foci of ossification in the dermis since early childhood. These foci gradually become deeper and invade the muscles and fascia. Other mutations of the same gene lead to fibrous bone dysplasia, pseudohypoparathyroidism, pseudopseudohypoparathyroidism or McCune Albright syndrome (see these terms)

Anesthetic implications:

No cases published.

By analogy, we can probably propose the same precautions as in case of progressive ossifying myositis, i.e.:

-        risk of difficult intubation (limited mobility of the cervical spine, limited opening of the mouth); fiberoptic intubation is recommended (even if intubation seems easy) because direct laryngoscopy can traumatize the temporomandibular joint and lead to its ossification.

-        restrictive syndrome, frequent pulmonary infections.

-        any trauma to the tissues can initiate a focus of ectopic ossification (IM, IV). Difficult local regional anesthesia techniques. It is recommended to administer corticosteroids perioperatively in order to prevent any ossification episode.

References :

-        Faust RA, Shore EM, Stevens CE, Xu M, Shah S et al.
Progressive osseous heteroplasia in the face of a child. 
Am. J. Med. Genet 2003; 118A: 71-5.

Updated: May 2022