Osteogenesis imperfecta (OI) is a heterogenous group of genetic disorders of bone fragility. OI type V is an autosomal-dominant disease characterized by calcification of the forearm interosseous membrane, radial head dislocation, a subphyseal metaphyseal radiodense line, and hyperplastic callus formation; the causative mutation involved in this disease has not been discovered yet. Using linkage analysis in a four-generation family and whole-exome sequencing, we identified a heterozygous mutation of c.-14C>T in the 5'-untranslated region of a gene encoding interferon-induced transmembrane protein 5 (IFITM5). It completely cosegregated with the disease in three families and occurred de novo in five simplex individuals. Transfection of wild-type and mutant IFITM5 constructs revealed that the mutation added five amino acids (Met-Ala-Leu-Glu-Pro) to the N terminus of IFITM5. Given that IFITM5 expression and protein localization is restricted to the skeletal tissue and IFITM5 involvement in bone formation, we conclude that this recurrent mutation would have a specific effect on IFITM5 function and thus cause OI type V.
A TiO2/VO2 oxide double‐layer nanocrossbar to overcome the sneak path problem in bipolar resistive memory is proposed. TiO2 and VO2 thin films function as a bipolar resistive memory and a bidirectional switch, respectively. The new structure suggests that ultrahigh densities can be achieved with a 2D nanocrossbar array layout. By stacking into a 3D structure, the density can be even higher.
We investigated the formation of nanowhiskers by means of air plasma dry etching using diamond films of two different kinds: as-grown diamond films and films with molybdenum (Mo) deposits. As for the as-grown diamond films, nanowhiskers were found to form preferentially at grain boundaries of diamond crystals. Auger depth profile analysis of the etched films revealed a progressive enrichment by Mo toward the whisker tip, resulting from accidental sputtering of Mo substrate holder. With dry etching of diamond films with preformed Mo deposits, well-aligned whiskers 100 nm in diameter were found to form uniformly over the entire film surface with a population density of 30/μm2. From these findings, it follows that Mo deposits serve as micromasks for the formation of the nanowhiskers. It was also confirmed that these whiskers showed excellent field-emission behavior.
Hereditary dentin defects are divided into dentinogenesis imperfecta and dentin dysplasia. We identified a family segregating severe dentinogenesis imperfecta. The kindred spanned four generations and showed an autosomal-dominant pattern of inheritance. The proband was a child presenting with a severely affected primary dentition, with wide-open pulp chambers and multiple pulp exposures, resembling a DGI type III (DGI-III) pattern. We hypothesized that a mutation in the DSPP gene is responsible for this severe phenotype. Mutational analyses revealed a novel mutation (c.53T>A, p.V18D) near the intron-exon boundary in the third exon of the DSPP gene. We analyzed the effect of the mutation by means of an in vitro splicing assay, which revealed that the mutation did not affect pre-mRNA splicing. Further studies are needed for a better understanding of the nature of the disease and the development of an appropriate treatment strategy.
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