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Congenital knee dislocation in a 49,XXXXY boy
R H Sijmons1, A J van Essen, J D Visser
1Department of Medical Genetics, University of Groningen, The Netherlands.
Journal of Medical Genetics
|April 1, 1995
Summary
A 12-year-old boy with 49,XXXXY karyotype experienced congenital knee dislocation and joint laxity. This case highlights the importance of karyotyping for patients with joint malformations and developmental delays.
Area of Science:
- Genetics
- Pediatrics
- Orthopedics
Background:
- Congenital joint dislocations and laxity can be associated with chromosomal abnormalities.
- The 49,XXXXY karyotype is a rare aneuploidy with variable clinical manifestations.
Observation:
- A 12-year-old male presented with bilateral congenital knee dislocations, right hip dislocation, and generalized joint laxity.
- Cytogenetic analysis revealed a 49,XXXXY karyotype.
Findings:
- While joint hyperlaxity is a known feature of 49,XXXXY syndrome, congenital knee dislocation has not been previously reported in this condition.
- The patient's presentation suggests a potential link between 49,XXXXY and severe congenital joint malformations.
Implications:
- This case expands the known phenotype of 49,XXXXY syndrome.
- It underscores the recommendation for karyotyping in infants with congenital joint dislocations or laxity, especially when accompanied by other malformations or psychomotor delay, to identify underlying chromosomal abnormalities.
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