[MIM 265 800]

Rare osteochondrodysplasia transmitted on an autosomal recessive mode. The painter Toulouse Lautrec suffered from it. It combines osteosclerosis, bone fragility and short stature... It is a lysosomal disease caused by mutations in the gene coding for cathepsin K (1q21). The mutation makes the osteoclasts unable to destroy some bone matrix proteins, which makes the bones abnormally dense but fragile.

Clinical presentation:

-        short stature (adult: 135-150 cm)

-        delayed closure of the anterior and posterior fontanelles

-        hypoplasia of the lower jaw with gradual disappearance of the mandibular angle; small mouth opening with lingual protrusion caused by relative macroglossia; poorly implanted and decayed teeth

-        hands and feet are short and massive due to the osteolysis of the terminal phalanx of fingers/toes

-        dysplasia of the clavicles

-        pathological fractures

-        sometimes obstructive sleep apnea requiring nocturnal non-invasive ventilation, or even a tracheostomy

-        frequent spondylolisthesis

Anesthetic implications:

small mouth opening, difficult intubation and ventilation ; brittle bones: risk of fracture ! obstructive sleep apnea; fragile teeth;  difficult neuraxial block in case of scoliosis (but some successfully blocks have been reported).

References : 

-         Abourazzak S, Chaouki S, Akodad Z, Boubou M, Atmani S, El Biaz M, Hida M. 
Apnées du sommeil et retard statral révélant une pycnodysostose. 
Arch Pédiatr 2013 ; 20 : 307-10.

-        Barnard B, Hiddema W. 
Pycnodysostosis with the focus on clinical and radiological findings. 
S Afr J Rad 2012; 16: 74-6.

-        Puri R, Saxena A, Mittal A et al. 
Pycnodysostosis : an anaesthetic approach to this rare genetic disorder. 
Case reports in Anesthesiology 2013; ID 716756

-        Herd RS, Sprung J, Weingarten TN. 
Primary osteolysis syndromes: beware of difficult airway. 
Pediatr Anesth 2015; 25: 727-37.

-        Kazawa M, Fugagawa A, Ito H, Toyama S, Makita K.
Risk of difficult intubation may increase with age in pediatric patients with pycnodysostosis.
Pediatr Anesth 20116; 26: 567-8.

Updated: Octobre 2018