(Metatropic dysplasia II, Kniest dysplasia, pseudometatroptic dysplasia, Swiss Cheese cartilage syndrome)

Incidence < 1/106.Autosomal dominant transmission of mutations in the COL2A1 gene (12q13.11-q13.2) coding for type II collagen. Most of the cases are due to heterozygous de novo mutations in the COL2A1 gene .

Severe collagenopathy of type II characterized by a trunk and short limbs, prominent joints and midfeace hypoplasia (round face with a flattened nose root). Sometimes abnormalities of tracheal cartilage with tracheomalacia.

The disease manifests at birth.

Common signs include cleft palate (sometimes associated with Pierre Robin syndrome), a kyphotic scoliosis, an early osteoarthritis, a severe myopia (substantial risk of retinal detachment), and a progressive deafness. In general, the intelligence is normal. Radiological diagnosis: thickened and deformed epiphyses, absent femoral head, enlarged upper femoral metaphyses , platyspondyly and other vertebral malformations.

At the histology of cartilage: presence of intracytoplasmic inclusions in chondrocytes with a matrixrich in vacuoles (whence

the term of 'cartilage into Swiss cheese'). The prognosis depends on the presence of joint malformations and vertebral anomalies.

Anesthetic implications:

risk of difficult intubation increasing with age; in case of stridor, suspect a tracheomalacia; check the stability of the atloaxoid articulation. Contractures of the joints; difficult neuraxial blocks.

References : 

• Hasegawa-Moriyama M, Iwasaki T, Mukaihara K, Masuda M et al.
  Unsuccessful tracheal intubation in a patient with Kniest dysplasia undergoing repeated general anesthesia: a case report.
  JA Clinical Reports 2018; 4; 41
• Segawa Y, Enomoto H, Nakagawa T, Iijima Y.
  Growth causes difficult intubation in a patient with Kniest dysplasia.
  J Anesth 2001; 15: 104-5
• Salik I, Kubal K, Barst S.
  Anesthetic implications of a patient with Kniest dysplasia and mitochondrial disease: a case report.
  A&A Practice 2018, in press

Updated: October 2018