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Temporal bone pathology of two infants with Larsen's syndrome
1Department of Otolaryngology, Teikyo University, School of Medicine, Tokyo, Japan.
Insights
This study describes two infants with Larsen syndrome, detailing new temporal bone pathologies. Findings suggest a widespread developmental issue affecting skeletal, facial, and auditory structures.
Area of Science:
- Genetics
- Pediatrics
- Otolaryngology
Background:
- Larsen syndrome is a rare genetic disorder characterized by multiple joint dislocations and distinctive facial features.
- Previous descriptions primarily focused on skeletal and facial abnormalities.
Observation:
- Two infants diagnosed with Larsen syndrome presented with severe joint dislocations, unusual facial features, and significant bony abnormalities.
- Detailed examination revealed specific temporal bone pathologies, including malleus and incus dislocations, abnormal stapes/footplate, and persistent mesenchyme in the middle ear spaces.
Findings:
- Histological analysis of the temporal bones in both cases demonstrated maldevelopment.
- Specific findings included dislocation of the malleus and incus, abnormal stapes or footplate, and incomplete development of mastoid air cells and labyrinthine structures.
- The presence of mesenchyme in the attic and mesotympanum indicated arrested development.
Implications:
- These findings expand the known phenotypic spectrum of Larsen syndrome to include significant otological abnormalities.
- Suggests a generalized developmental anomaly affecting not only the skeletal system but also the craniofacial and temporal bone structures.
- Highlights the importance of audiological and otological assessments in patients diagnosed with Larsen syndrome.
Abstract:
Two infants who had multiple joint dislocations, unusual facies, and bony abnormalities, typical of the syndrome first reported by Larsen et al. (J. Pediatr., 37 (1950) 574-581) are described. This report expands Larsen's syndrome to include the following findings of temporal bone pathology. Case 1 (one year and 8 months old) showed dislocation of the malleus and incus, an abnormal foot plate, mesenchyme remaining in the attic and mesotympanum, poor development of the mastoid air cells, and poor development of the labyrinth. Case 2 (3 years and 6 months old) showed dislocation of the malleus and incus, mesenchyme remaining in the attic and mesotympanum, and an abnormal stapes. These histological findings suggest that a maldevelopment similar to that which occurs in the skeletal system occurs in the temporal bones as well as in the face and extremities including many joints.