Can Multiple Hereditary Exostoses Overlap With Mesomelic Dysplasia?

Background: We studied an unusual combination of severe short stature, mesomelia (Leri-Weill dyschondrosteosis syndrome), and multiple exostosis in several family subjects over three generations. The pattern of inheritance was compatible with autosomal dominant.

Methods: Of 21 affected members over three generations, shortness of stature, associated with mesomelia resembling Leri-Weill dyschondrosteosis syndrome with no exostoses was evident in three family subjects. The rest of the family subjects manifested with normal height, and yet multiple exostoses. In this family, the skeletal manifestations were sufficiently variable for the presentation to be with either short stature or scoliosis, a Madelung' deformity, or with severe hallux valgus associated with exostosis and with Leri-Weill dyschondrosteosis syndrome.

Results: Subjects with structural chromosomal aberrations of the proband IV-7, who manifested with normal height but with multiple exostoses were excluded via 20 CAG-banded mitoses (there were no microdeletions or microduplication after performing Array-CGH-analysis). In addition, DNA examination for subject IV-8 (male cousin of the proband showed short stature and Leri-Weill dyschondrosteosis syndrome) revealed no evidence of SHOX deletions.

Conclusion: We described a multigenerational non-consanguineous North African family , in which mesomelic dysplasia, whose clinical and radiological phenotypes resembled dyschondrosteosis, was a prominent feature in three family subjects. Multiple exostoses were evident in several other family subjects (most were with normal height). We would like to emphasize the variability in the phenotypic expression of multiple exostosis, especially the confusion that might arise when the condition appears both clinically and radiologically to be more complicated, and the overall picture might then be overlapped with one of the other bone dysplasias such as Leri-Weill dyschondrosteosis syndrome.