Anatomical characteristics and potential gene mutation sites of a familial recurrent patellar dislocation.

BACKGROUND: Recurrent patellar dislocation is the result of anatomical alignment and imbalance of restraint of bone and soft tissue. We investigate the anatomical characteristics of the knee joint in a family of patients with recurrent patella dislocation, and to screen the possible pathogenic genes in this family by whole exome sequencing in 4 patients and 4 healthy subjects, so as to provide theoretical basis for the pathogenesis of this disease. METHODS: The data related to patella dislocation were measured by imaging data. The peripheral blood DNA of related family members was extracted for the whole exome sequencing, and then the sequencing results were compared with the human database. By filtering out synonymous variants and high-frequency variants in population databases, and then integrating single nucleotide non-synonymous variants of family members, disease-causing genes were found. RESULTS: All patients in this family have different degrees of abnormal knee anatomy, which is closely related to patella dislocation. The sequencing results of patients and normal persons in this patella dislocation family were compared and analyzed, and the data were filtered through multiple biological databases. Find HOXB9 (NM_024017.4:c.404A>G:p.Glu135Gly),COL1A1(NM_000088.3:c.3766G>A:p.Ala1256Thr),GNPAT(NM_014236.3:c1556A>G:p.Asp519Gly),NANS(NM_018946.3:c.204G>C:p.Glu68Asp),SLC26A2(NM_000112.3:c.2065A>T:p.Thr689Ser) are nonsynonymous variants (MISSENSE). Through Sanger sequencing, the identified mutations in HOXB9 and SLC26A2 genes were only present in samples from patients with recurrent patellar dislocation. CONCLUSIONS: The patients with recurrent patellar dislocation had markedly abnormal knee anatomy in this family. HOXB9 gene and SLC26A2 gene were found to be the possible pathogenic genes or related genes for patella dislocation.

[Tricaicium phosphate complex pre-loaded with bone morphogenetic protein-2 or platelet derived growth factor-BB for repairing critical-size cranial defects in SD rats].

OBJECTIVE: To observe the effect of a new biomaterial in promoting the bone regeneration for repairing critical-size cranial defects in SD rats. METHODS: Critical-size cranial defects were induced in 3-month-old male Sprague-Dawley rats and repaired with the implants of calcium phosphate from growth factor enhanced matrix 21 (CaPfromGEM21, control), CaPfromGEM21 preloaded with 10 ng bone morphogenetic protein-2 (BMP-2), CaPfromGEM21 preloaded with 100 ng BMP-2, CaPfromGEM21 preloaded with 0.3 µg platelet-derived growth factor-BB (PDGF-BB), or CaPfromGEM21 preloaded with 3 µg PDGF-BB. The defects were examined 6 weeks after the surgery with X-ray, micro-CT, HE staining and quantitative assessments. RESULTS: X-ray showed defect repair in all the groups. The fracture line became obscure, and the defects were almost fully repaired by the regenerated bone tissues in PDGF-BB group. Micro-CT demonstarted new bone formation in the defects. The new bone volume was significantly greater in PDGF-BB groups than in BMP-2 groups (P<0.05). HE staining revealed the presence of new bones in the defects and new vessels in and around the new bones without inflammatory cells. The new bone area fraction was significantly greater in 10 ng BMP-2 group and 0.3 µg PDGF-BB group than in the control group (P<0.05), and the new vessel density was similar in the all the 4 cytokine-preloaded groups and all significantly greater than that in the blank and CaPfromGEM21 control group (P<0.05). CONCLUSION: CaPfromGem21 combined with BMP-2 or PDGF-BB has good biocompatibility and can better promote bone regeneration for repairing bone defects.