No abstract

Myosin XVA is an unconventional myosin which has been implicated in autosomal recessive nonsyndromic hearing impairment (ARNSHI) in humans. In Myo15A mouse models, vestibular dysfunction accompanies the autosomal recessive hearing loss. Genomewide homozygosity mapping and subsequent fine mapping in two Turkish families with ARNSHI revealed significant linkage to a critical interval harboring a known deafness gene MYO15A on chromosome 17p13.1‐17q11.2. Subsequent sequencing of the MYO15A gene led to the identification of a novel missense mutation, c.5492G → T (p.Gly1831Val) and a novel splice site mutation, c.8968 − 1G → C. These mutations were not detected in additional 64 unrelated ARNSHI index patients and in 230 Turkish control chromosomes. Gly1831 is a conserved residue located in the motor domains of the different classes of myosins of different species. Molecular modeling of the motor head domain of the human myosin XVa protein suggests that the Gly1831Val mutation inhibits the powerstroke by reducing backbone flexibility and weakening the hydrophobic interactions necessary for signal transmission to the converter domain. © 2007 Wiley‐Liss, Inc.

We report on a 17‐year‐old patient with midline defects, ocular hypertelorism, neuropsychomotor development delay, neonatal macrosomy, and dental anomalies. DNA copy number investigations using a Whole Genome TilePath array consisting, of 30K BAC/PAC clones showed a 6.36 Mb deletion in the 9p24.1–p24.3 region and a 14.83 Mb duplication in the 20p12.1–p13 region, which derived from a maternal balanced t(9;20)(p24.1;p12.1) as shown by FISH studies. Monosomy 9p is a well‐delineated chromosomal syndrome with characteristic clinical features, while chromosome 20p duplication is a rare genetic condition. Only a handful of cases of monosomy 9/trisomy 20 have been previously described. In this report, we compare the phenotype of our patient with those already reported in the literature, and discuss the role of DMRT, DOCK8, FOXD4, VLDLR, RSPO4, AVP, RASSF2, PROKR2, BMP2, MKKS, and JAG1, all genes mapping to the deleted and duplicated regions. © 2011 Wiley Periodicals, Inc.

This study presented the synthesis and characterization of glucosamine (GlcN) modified poly (ethylene glycol) (PEG) hydrogels. The chemical structure was characterized by Fourier transform infrared (FTIR) and proton nuclear magnetic resonance ( 1 H NMR) spectroscopy. The morphology of hydrogels was observed by scanning electron microscopy (SEM). The results indicated that GlcN was successfully incorporated into PEG hydrogel network. Moreover, the data of the swelling ratio showed that the ratio of GlcN-modified PEG hydrogels was lower than that of pure poly(ethylene glycol) diacrylated (PEGDA). Biocompatibility of unreacted GlcN monomer and GlcN-modified hydrogels was also evaluated in vitro. Compared with glucosamine hydrochloride, 2 and 5 mM N-acroloyl-glucosamine monomer exhibited no toxicity against bone marrow stromal cells (BMSCs), while with the concentration increased to 10 mM, cell viability appeared to decrease. However, when BMSCs were encapsulated in GlcN-modified hydrogels via photopolymerization method, cells remained vigorous viability. Metabolic activity of the encapsulated cells demonstrated GlcN-modified hydrogels was favorable for cell proliferation. Compared with free GlcN, covalent binding GlcN showed lower cytotoxicity and higher cell proliferation properties. As a result, GlcN-modified PEGDA hydrogels could be used as safe and injectable cell carriers for in situ tissue engineering applications.