Child, Preschool ; Coffin-Lowry Syndrome ; diagnosis ; psychology ; Diagnosis, Differential ; Humans ; Male

Coffin-Lowry-Syndrome (CLS) is a X-linked mental retardation characterized by skeletal dysplasia and premature tooth loss. We and others have previously demonstrated that the ribosomal S6 kinase RSK2, mutated in CLS, is essential for bone and cementum formation; however, it remains to be established whether RSK2 plays also a role in mechanically induced bone remodeling during orthodontic tooth movement (OTM). We, therefore, performed OTM in wild-type (WT) mice and Rsk2-deficient mice using Nitinol tension springs that were fixed between the upper left molars and the incisors. The untreated contralateral molars served as internal controls. After 12 days of OTM, the jaws were removed and examined by micro-computed tomography (µCT), decalcified histology, and immunohistochemistry. Our analysis of the untreated teeth confirmed that the periodontal phenotype of Rsk2-deficient mice is characterized by alveolar bone loss and hypoplasia of root cementum. Quantification of OTM using µCT revealed that OTM was more than two-fold faster in Rsk2-deficient mice as compared to WT. We also observed that OTM caused alveolar bone loss and root resorptions in WT and Rsk2-deficient mice. However, quantification of these orthodontic side effects revealed no differences between WT and Rsk2-deficient mice. Taken together, Rsk2 loss-of-function accelerates OTM in mice without causing more side effects.
Animals ; Coffin-Lowry Syndrome ; Dental Cementum ; Mice ; Root Resorption ; Tooth Movement Techniques ; X-Ray Microtomography

Coffin-Lowry syndrome (CLS) is a rare X-linked hereditary disorder characterized by moderate to severe mental retardation, facial dysmorphism, tapering fingers, and skeletal deformity. A 12-month-old boy was referred to our pediatric clinic for his developmental delay and seizure with fever. The boy exhibited a coarse facial appearance characterized by prominent, high-arched eyebrow, broad nose, downward palpebral fissure, high arched palate, hypodontia. The boy also showed finger tapering and puffy hand. Hypotonia, hyperextensible fingers and hypermobility of the joint were seen. Based on these findings, he was diagnosed as having Coffin-Lowry syndrome. We report a case of Coffin-Lowry syndrome with reference.
Anodontia ; Coffin-Lowry Syndrome* ; Congenital Abnormalities ; Eyebrows ; Fever ; Fingers ; Hand ; Humans ; Infant ; Intellectual Disability ; Joints ; Male ; Muscle Hypotonia ; Nose ; Palate ; Seizures

OBJECTIVE: To identify potential mutations of the CLS gene in a Chinese pedigree affected with Coffin-Lowry syndrome. METHODS: Whole exome sequencing was applied to detect potential mutation in the proband, and the result was verified by Sanger sequencing. RESULTS: The proband was found to carry a c.966_967delAA (p.Arg323Thr fs*11) deletional mutation in the RPS6KA3 gene. The same mutation was also found in his mother. CONCLUSION The c.966_967delAA (p.Arg323Thr fs*11) deletional mutation of the RPS6KA3 gene probably underlies the disorder in this pedigree.
Asian Continental Ancestry Group ; China ; Coffin-Lowry Syndrome ; genetics ; Humans ; Mutation ; Pedigree ; Ribosomal Protein S6 Kinases, 90-kDa ; genetics ; Sequence Deletion