MATR3 F115C knock-in mice do not exhibit motor defects or neuropathological features of ALS.

The F115C mutation in the MATR3 gene has been linked to amyotrophic lateral sclerosis (ALS). To determine the pathogenicity of the F115C mutation and the mechanism by which this mutation causes ALS, we generated mice that harbor the F115C mutation in the endogenous murine Matr3 locus. Heterozygous or homozygous MATR3 F115C knock-in mice were viable and did not exhibit motor deficits up to 2 years of age. The mutant mice showed no significant differences in the number of Purkinje cells or motor neurons compared to wild-type littermates. Neuropathological examination revealed an absence of MATR3 and TDP-43 pathology in Purkinje cells and motor neurons in the mutant mice. Together, our results suggest that the F115C mutation in MATR3 may not confer pathogenicity.

The significance of serum phosphate level on healing index and its relative effects in skeletally immature and mature patients with hypophosphatemic rickets.

The aim of this study was to find out the ideal cut-off level of phosphate for safe healing when deformity correction and concomitant lengthening are indicated in the two different skeletal maturity groups of patients with rickets. Thirty-nine hypophosphatemic rickets patients were selected for the study and were divided into two groups: 27 skeletally immature (group IM) and 12 skeletally mature (group M). The outcomes were evaluated with respect to the healing index (HI), laboratory findings, and complications with the mean follow-up of 5.1 years (range, 3.1-7.9). The healing index (HI) of group IM was 1.44 month/cm and HI of group M was 1.68 month/cm. The negative correlation between the level of serum phosphate and HI in group M (coefficient=-0.94) was evaluated to be less than the correlation in group IM (coefficient=-0.50), indicating that the HI is more likely to be affected by serum phosphate in group M than in group IM. Preoperative serum phosphate levels of 2.3 mg/dL and 2.6 mg/dL were analyzed to be the cut-off values of group IM and group M, respectively, in which the cut-off points divided the series into two groups having the most significantly different HI.