Kniest dysplasia

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Classification according to ICD-10
Q78.9 Osteochondrodysplasia, unspecified
Q77.7 Dysplasia spondyloepiphysaria
ICD-10 online (WHO version 2019)

The Kniest dysplasia or Kniest Syndrome is an inherited developmental disorder of the skeleton ( skeletal ) with severe short stature and characteristic changes in the skeleton. The disease is one of the collagenopathies .

It was first described in 1952 by the German pediatrician Wilhelm Kniest .

X-ray of a child with knee dysplasia and the typical changes in the pelvis and thighs

distribution

The frequency is not known.

causes

It is based on mutations in the COL2A1 gene at location 12q13.11-q13.2. This gene is involved in the production of type II collagen , which is mainly needed for the structure of the eyeball, cartilage and in the inner ear. The genetic deviation leads to an altered structure of type II collagen, which prevents bones, joints and various connective tissues from developing properly.

The inheritance is autosomal dominant . Mostly these are heterozygous new mutations ; that is, the parents of the child with Kniest's dysplasia are usually not affected themselves. If those affected have children themselves, the probability of inheriting Kniest's dysplasia is 50%.

Clinical manifestations

Kniest's dysplasia has a variable spectrum from the most severe and lethal to mild forms.

Clinical criteria are:

  • Severe, disproportionate short stature with shortening of the trunk, already onset in the infant, the adult height is 106 cm to 156 cm or up to 145 cm, depending on the source
  • thoracic kyphosis and lumbar lordosis
  • short extremities with distended joints that are often restricted in their mobility
  • Flat mid-face with sunken nose bridge

In addition, in 50% there are cleft palates and hearing loss and, less often, myopia .

diagnosis

The x-ray of the spine shows platyspondyly , vertebral bodies that have a pointed ventral aspect , and vertical cleft vertebrae can occur in infants . The pelvic blades are wide with underdevelopment of the lower parts of the iliac bone , considerably widened, clumsy and short femoral necks, shortened and metaphyseally distended tubular bones.

Large epiphyses and late appearance of the femoral head in the 2nd to 3rd year of life are further criteria, as are megaepiphyses in the knee and hip joint.

Genetic evidence or exclusion can take place before birth; the shortened extremities can be detected sonographically .

Differential diagnosis

To be differentiated are the spondyloepiphyseal dysplasia , the dyssegmental dysplasia and the metatropic dysplasia .

Histologically, there are “holes” in the cartilage that are specific to the Kniest syndrome .

therapy

A causal treatment is not possible.

The prognosis is determined by the severity of the joint and vertebral abnormalities.

literature

  • W. Kniest, B. Leiber: Kniest Syndrome. In: Monthly for Pediatrics. Volume 125, Number 12, December 1977, pp. 970-973. PMID 600274 .
  • N. Ben Jamaâ, A. Masmoudi, C. Ghaffari, W. Limam, S. Siala-Gaigi: Kniest Dysplasia. In: La Tunisie médicale. Volume 90, Number 12, December 2012, pp. 902-903, ISSN  0041-4131 . PMID 23247797 .
  • J. Spranger, A. Winterpacht, B. Zabel: Kniest dysplasia: Dr. W. Kniest, his patient, the molecular defect. In: American journal of medical genetics. Vol. 69, No. 1, March 1997, pp. 79-84, ISSN  0148-7299 . PMID 9066888 .

Individual evidence

  1. ↑ a b c B. Leiber: The clinical syndromes. Syndromes, sequences and symptom complexes. Edited by G. Burg, J. Kunze, D. Pongratz, PG Scheurlen, A. Schinzel, J. Spranger, 7th edition. Urban & Schwarzenberg 1990, ISBN 3-541-01727-9 .
  2. ↑ W. Kniest: To differentiate the dyostosis enchondralis from the chondrodystrophy. In: Journal of Pediatrics. Vol. 70, No. 6, 1952, pp. 633-640, ISSN  0044-2917 . PMID 12995812 .
  3. ↑ Knee dysplasia. In: Genetics Home Reference. US National Library of Medicine, June 11, 2019, accessed June 23, 2019 .
  4. ↑ a b c d Kniest's dysplasia. In: Orphanet (Rare Disease Database).
  5. ↑ a b c W. Schuster, D. Färber (Ed.): Children's radiology. Imaging diagnostics. Volume 1, Springer, 1996, ISBN 3-540-60224-0 , pp. 332-337.
  6. ↑ Jürgen Spranger, Hartmut Menger, Johannes Correll, Peter Freisinger: Spondylo-epiphyseal dysplasia congenita (SEDC) & Kniest dysplasia . In: BKMF (Ed.): Small stature, yellow leaves . 3a, 2006, p. 6 .

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