A Novel PACS1 Variant Associated With Schuurs-Hoeijmakers Syndrome Phenotype in an Indigenous Descendant in Brazil: A Case Report.

Schuurs-Hoeijmakers syndrome, an autosomal dominant disorder associated with mutations in the PACS1 gene, was initially identified in two unrelated children of European descent from a cohort of individuals with intellectual disabilities. This gene alteration significantly reduced cranial cartilaginous structures, inducing craniofacial alterations predominantly in a dominant-negative fashion. In this paper, we report a novel variant of PACS1 associated with Schuurs-Hoeijmakers syndrome: a boy aged two years and nine months of indigenous descent presenting with motor stereotypies, atypical sensory searches, language delay, and low socio-interactional reciprocity. Whole exome sequencing confirmed the presence of a heterozygous missense mutation c.943C>T p. (Arg315Trp) in the PACS1 gene. The phenotypic profile identified was similar to the other cases of Schuurs-Hoeijmakers syndrome described in the literature. This report highlights the importance of considering the possibility of PACS1 gene alterations and a diagnosis of Schuurs-Hoeijmakers syndrome in patients presenting craniofacial alterations associated with autistic features, psychomotor and language development delay.

Xenotransplantation of human dental pulp stem cells in platelet-rich plasma for the treatment of full-thickness articular cartilage defects in a rabbit model.

Stem cells in platelet-rich plasma (PRP) scaffolds may be a promising treatment for cartilage repair. Human dental pulp stem cell (hDPSC) subpopulations have been identified to have substantial angiogenic, neurogenic and regenerative potential when compared with other stem cell sources. The present study evaluated the potential of hDPSCs in a PRP scaffold to regenerate full-thickness cartilage defects in rabbits. Full-thickness articular cartilage defects were created in the patellar groove of the femur of 30 rabbits allocated into three experimental groups: Those with an untreated critical defect (CTL), those treated with PRP (PRP) and those treated with stem cells in a PRP scaffold (PRP+SC). The patellar grooves of the femurs from the experimental groups were evaluated macroscopically and histologically at 6 and 12 weeks post-surgery. The synovial membranes were also collected and evaluated for histopathological analysis. The synovial lining cell layer was enlarged in the CTL group compared with the PRP group at 6 weeks (P=0.037) but not with the PRP+SC group. All groups exhibited low-grade synovitis at 6 weeks and no synovitis at 12 weeks. Notably, macroscopic grades for the area of articular cartilage repair for the PRP+SC group were significantly improved compared with those in the CTL (P=0.001) and PRP (P=0.049) groups at 12 weeks. Furthermore, histological scores (modified O'Driscoll scoring system) of the patellar groove articular cartilage in the PRP+SC and PRP groups, in which the articular cartilage was primarily hyaline-like, were significantly higher compared with those in the CTL group at 12 weeks (P=0.002 and P=0.007, respectively). The present results support the therapeutic use of hDPSCs for the treatment of full-thickness articular cartilage defects.