Neonatal myofibrillar myopathy type II associated with biallelic UNC-45B gene novel mutation and perinatal myasthenia as the core phenotype: A case report.

Myofibrillar myopathy (MFM) is characterized by phenotypic heterogeneity; decreased function of the myosin-directed chaperone, UNC-45B protein, leads to MFM II, which is characterized by slow progressive proximal myasthenia. Currently, only two studies have reported 11 cases worldwide. This study aimed to conduct genetic research and etiological analysis of a neonatal case of perinatal myasthenia who eventually died due to autonomic dyspnea. The case involved a newborn female admitted for weak cries and groaning. Physical examination revealed shallow and irregular spontaneous breathing, difficulty feeding, hip flexion and knee flexion in both lower limbs, hypotonia (level 1), less translation action, and inability to resist gravity. The child died at 23 days after birth. Gene testing, mutation analysis, and crystal structure analysis were conducted. Cell culture and plasmid construction were conducted, followed by western blot analysis. Pathological changes, including Z-line breakage, were observed in the muscle biopsies of different tissues. Gene testing showed that UNC-45B had a novel compound heterozygous mutation (c.2357T>A/p.Met786Lys, c.2591A>C/p.His864Pro), and in vitro functional experiments showed that the variants could lead to a decrease in protein expression. This study expands the UNC-45B mutation and phenotype spectrum by reporting an MFM II case in a Chinese patient for the first time.

[Osteogenetic effect of mechanical vibration on bone].

Mechanical loading is the main "instructive" factor of bone formation. The mechanism becomes the heat point in the field of bone science, biomedicine project and rehabilitation research. Mechanical vibration is one of the mechanic stimulation. Evidences show that vibration has obvious anabolic effect, and will have a broad landscape in the treatment of osteoporosis. But in the present studies, there were incorporated with the vibration frequency, and intensity, in particularly, few reports about the mechanism of vibration to bone. It will provide theoretic foundation for further systematic, sound research and its clinical application.