[MIM 177 170]

Rare form of spondylo-epi-metaphyseal dysplasia (see this term). Sporadic mutation or autosomal dominant transmission of a mutation of the COMP gene (19p13.1) coding for an oligomeric protein highly expressed in the extracellular matrix of the chondrocytes.

The size is normal at birth and the growth curve is normal until the age of 2 to 4 years. Adult height is between 82 and 130 cm.  Head circumference and facies are normal, on the contrary to achondroplasia. The hands and feet are short; the joints present  ligamentous hyperlaxity. Incomplete extension at the elbows and ulner deviation of the wrists. Bowing of the long bones and scoliosis are usual.

RX: small, fragmented and irregular epiphyses; anomalies of the metaphyses ; platyspondyly with anterior tonguing of the vertebral bodies the shape of which becomes normal after puberty. Hypoplasia or aplasia of the odontoid process.

Anesthetic implications:

no published cases. By analogy with achondroplasia: risk of difficult intubation, obstructive sleep apnea, restrictive syndrome, risk of spinal cord compression at the level of the atlantoaxial junction, narrow foramen magnum (very careful positioning). Regarding the endotracheal tube, the initial size should be choosen according to weight rather than age.

References : 

-         Geneviève D, Cormier-Daire V. 
Spondylo-epi-metaphyseal dysplasia, 
in Encyclopedia of molecular mechanisms of disease, edited by F Lang, 2012.

-         www. springerreference.com/index/chapterbid/109978 

-         Sisk EA, Heatley DG, Borowski BJ, Leverson GE, Pauli RM. 
Obstructive sleep apnea in children with achondroplasia: surgical and anesthetic considerations. 
Otolaryngol Head Neck Surg 1999; 120:248-54. 

-        Tamaro G, Pederiva F, Dibello D, Gregori M, Carbone M et al.
A child with a diminished linear growth and waddling gait.
J Pediatr 2018 ; 201 : 297-8.

Updated: January 2019