Multidisciplinary approach to the treatment of a patient with chondrodystrophic myotonia (Schwartz-Jampel vel Aberfeld syndrome): case report and literature review

Perlecan Knockdown Significantly Alters Extracellular Matrix Composition and Organization During Cartilage Development

Perlecan is a critical proteoglycan found in the extracellular matrix (ECM) of cartilage. In healthy cartilage, perlecan regulates cartilage biomechanics and we previously demonstrated perlecan deficiency leads to reduced cellular and ECM stiffness in vivo This change in mechanics may lead to the early onset osteoarthritis seen in disorders resulting from perlecan knockdown such as Schwartz-Jampel syndrome (SJS). To identify how perlecan knockdown affects the material properties of developing cartilage, we used imaging and liquid chromatography-tandem mass spectrometry (LC-MS/MS) to study the ECM in a murine model of SJS, Hspg2C1532Y-Neo Perlecan knockdown led to defective pericellular matrix formation, whereas the abundance of bulk ECM proteins, including many collagens, increased. Post-translational modifications and ultrastructure of collagens were not significantly different; however, LC-MS/MS analysis showed more protein was secreted by Hspg2C1532Y-Neo cartilage in vitro, suggesting that the incorporation of newly synthesized ECM was impaired. In addition, glycosaminoglycan deposition was atypical, which may explain the previously observed decrease in mechanics. Overall, these findings provide insight into the influence of perlecan on functional cartilage assembly and the progression of osteoarthritis in SJS.

Orthodontic management of a patient with Schwartz-Jampel Syndrome

The orthodontic diagnosis and comprehensive management of a 12.5-year-old Saudi girl, diagnosed with Schwartz-Jampel Syndrome (SJS) is presented. SJS is a rare autosomal recessive disorder that affects musculoskeletal structures of the body with clinical manifestations in the maxillofacial region. While few reports in the literature have discussed the dental aspects of the syndrome, this paper attempts to describe the full course of a two-phase comprehensive orthodontic treatment, and discuss its findings.