Pyknodysostosis

Changed by Prashant Mudgal, 25 Sep 2014
Back to revision history

Updates to Article Attributes

Body was changed:

Pyknodysostosis (osteopetrosis acro-osteolytica) is a rare autosomal recessive bone dysplasia characterised by osteosclerosis and short stature. The condition is also known as Toulouse-Lautrec syndrome, named after the famous French artist who was thought to be afflicted with the disease.

Pathology

PyknodyostosisPyknodysostosis is a lysosomal disorder due to genetic deficiency in Cathepsin K which has been mapped to chromosome 1q21. Cathepsin K is essential for normal osteoclast function.

Clinical presentation

Patients present in early childhood with:

  • short stature particularly limbs
  • delayed closure of cranial sutures 
  • frontal and occipital bossing
  • short broad hands and hypoplasia of nails
  • multiple long bone fractures following minimal trauma

Radiographic features

Osteosclerosis with narrowed medullary cavities is the main generalised imaging finding. Long bone fractures are common. Obtuse angle of the mandible. Lack / abnormal/abnormal teeth. 

Plain film / CT/CT
Hands
  • short, stubby fingers
  • partial agenesis / aplasia/aplasia of terminal phalanges simulating acro-osteolysis 
  • delayed bone age 
Cranial and maxillofacial
  • marked delay in sutural closure
  • frontoparietal bossing
  • calvarial thickening
  • wormian bones (lambdoidal region)
  • relative proptosis
  • nasal beaking
  • obtuse mandibular gonial angle often with relative prognathism
  • persistence of primary teeth
Other

Etymology

Derived from the greek terms pucnos = dense , dys = defective , ostosis = bone conditiioncondition 

Differential diagnosis

General considerations include

  • -<p><strong>Pyknodysostosis</strong> (osteopetrosis acro-osteolytica) is a rare autosomal recessive bone dysplasia characterised by osteosclerosis and short stature. The condition is also known as <strong>Toulouse-Lautrec syndrome</strong>, named after the famous French artist who was thought to be afflicted with the disease.</p><h4>Pathology</h4><p>Pyknodyostosis is a lysosomal disorder due to genetic deficiency in Cathepsin K which has been mapped to chromosome 1q21. Cathepsin K is essential for normal osteoclast function.</p><h4>Clinical presentation</h4><p>Patients present in early childhood with :</p><ul>
  • +<p><strong>Pyknodysostosis</strong> (osteopetrosis acro-osteolytica) is a rare autosomal recessive bone dysplasia characterised by osteosclerosis and short stature. The condition is also known as <strong>Toulouse-Lautrec syndrome</strong>, named after the famous French artist who was thought to be afflicted with the disease.</p><h4>Pathology</h4><p>Pyknodysostosis is a lysosomal disorder due to genetic deficiency in Cathepsin K which has been mapped to chromosome 1q21. Cathepsin K is essential for normal osteoclast function.</p><h4>Clinical presentation</h4><p>Patients present in early childhood with:</p><ul>
  • -</ul><h4>Radiographic features</h4><p><a href="/articles/osteosclerosis">Osteosclerosis</a> with narrowed medullary cavities is the main generalised imaging finding. Long bone fractures are common. Obtuse angle of the mandible. Lack / abnormal teeth. </p><h5>Plain film / CT</h5><h6>Hands</h6><ul>
  • +</ul><h4>Radiographic features</h4><p><a href="/articles/osteosclerosis">Osteosclerosis</a> with narrowed medullary cavities is the main generalised imaging finding. Long bone fractures are common. Obtuse angle of the mandible. Lack/abnormal teeth. </p><h5>Plain film/CT</h5><h6>Hands</h6><ul>
  • -<li>partial agenesis / aplasia of terminal phalanges simulating <a href="/articles/acro-osteolysis-1">acro-osteolysis </a>
  • +<li>partial agenesis/aplasia of terminal phalanges simulating <a href="/articles/acro-osteolysis-1">acro-osteolysis </a>
  • -</ul><h4>Etymology</h4><p>Derived from the greek terms <em>pucnos</em> = dense , <em>dys</em> = defective , <em>ostosis </em>= bone conditiion </p><h4>Differential diagnosis</h4><p>General considerations include</p><ul>
  • +</ul><h4>Etymology</h4><p>Derived from the greek terms <em>pucnos</em> = dense , <em>dys</em> = defective , <em>ostosis </em>= bone condition </p><h4>Differential diagnosis</h4><p>General considerations include</p><ul>

ADVERTISEMENT: Supporters see fewer/no ads