We present the clinical and genetic findings for a Chinese family with X-linked non-syndromic hearing loss in which the affected males showed congenital profound sensorineural hearing impairment. In two affected broth...We present the clinical and genetic findings for a Chinese family with X-linked non-syndromic hearing loss in which the affected males showed congenital profound sensorineural hearing impairment. In two affected brothers, the computer tomography of temporal bone showed bilateral dilation of the internal auditory canal with fistulous communication between the lateral canal and the basal cochlear turn, which is consistent with the typical DFNX2 phenotype. A missense mutation （c.647G→A） in the POU3F4 gene caused a substitu- tion from glycine to glutamic acid at position 216 （p.G216E）, and this mutation was found to consistently cosegregate with the deafness phenotype in the family. The mutation resulted in the loss of function of the POU3F4 by decreasing the affinity between the protein and DNA, as shown in silico by the structural analysis. Prenatal diagnosis of pregnant proband of this family revealed the c.647G→A mutation in DNA extracted from the amniotic fluid surrounding the fetus. The appropriate use of genetic testing and prenatal diagnosis plays a key role in reducing the recurrence of genetic defects in high-risk families.展开更多
Non-syndromic low-frequency sensorineural hearing loss （LFSNHL） is an unusual type of hearing loss in which frequencies ≤2000 Hz predominantly are affected. To date, different mutations in two genes, DIAPHI and WFS...Non-syndromic low-frequency sensorineural hearing loss （LFSNHL） is an unusual type of hearing loss in which frequencies ≤2000 Hz predominantly are affected. To date, different mutations in two genes, DIAPHI and WFSI, have been found to be associated with LFSNHL. Here, we report a five-generation Chinese family with postlingual and progressive LFSNHL. We mapped the disease locus to a 2.5 Mb region on chromosome 4p16 between markers SNP_A-2167174 and D4S431, overlapping with the DFNA6/14/38 locus. Sequencing of candidate gene revealed a heterozygous c.2086C〉T substitution in exon 8 of WFS1, leading to p.H696Y substitution at the C-terminus of Wolframin （WFS 1）. In addition, we performed mutational screening of WFS1 in 37 sporadic patients, 7--50 years of age, with LFSNHL. We detected a heterozygous c.2108G〉A substitution in exon 8 of WFSI, leading to p.R703H substitution in a patient. The H696 and R703 in WFS1 are highly conserved across species, including human, orangutan, rat, mouse, and frog （Xenopus）, Sequence analysis demonstrated the absence of c.2086C〉T or c.210gG〉A substitutions in the WFS1 genes among 200 unrelated control subjects of Chinese background, supporting the hypothesis that they represent causative mutations, and not rare polymorphisms. Our data provide additional molecular and clinical information for establishing a better genotype-phenotype correlation for LFSNHL.展开更多
X-ray diffraction (XRD), ball-disc friction and wearing machine and draw-bead test were introduced to investigat the strcusture and workability of IF sheet steel electrogalvanized deposits prepared from sulphate solut...X-ray diffraction (XRD), ball-disc friction and wearing machine and draw-bead test were introduced to investigat the strcusture and workability of IF sheet steel electrogalvanized deposits prepared from sulphate solution system. It was shown that the picking-up of the zinc coating on die strengthened with the increasing of friction factor which was originally affected by the coating's structure. Duing forming, (00X) planes (X= 2, 4) preferential orientation of zinc deposits increased, which resulted in enhanc ing the coating's friction behaviors. Therefore, the forming mechanism of electrogalvedzed deposit was demonstrated that both friction and the stricking -up behaviors of the coating are intensified simultaneously and affect each other.展开更多
基金supported by the funding from the National High Technology Research and Development Program of China (863 Program) to Huijun Yuan (No.2007AA02E466)Key Project of National Natural Science Foundation of China to Huijun Yuan (Nos.81030017, 30571018) and Xuezhong Liu (No. 30528025)
文摘We present the clinical and genetic findings for a Chinese family with X-linked non-syndromic hearing loss in which the affected males showed congenital profound sensorineural hearing impairment. In two affected brothers, the computer tomography of temporal bone showed bilateral dilation of the internal auditory canal with fistulous communication between the lateral canal and the basal cochlear turn, which is consistent with the typical DFNX2 phenotype. A missense mutation （c.647G→A） in the POU3F4 gene caused a substitu- tion from glycine to glutamic acid at position 216 （p.G216E）, and this mutation was found to consistently cosegregate with the deafness phenotype in the family. The mutation resulted in the loss of function of the POU3F4 by decreasing the affinity between the protein and DNA, as shown in silico by the structural analysis. Prenatal diagnosis of pregnant proband of this family revealed the c.647G→A mutation in DNA extracted from the amniotic fluid surrounding the fetus. The appropriate use of genetic testing and prenatal diagnosis plays a key role in reducing the recurrence of genetic defects in high-risk families.
基金supported by the National High Technology Research and Development Program of China(863 Program) to Huijun Yuan(No.2007AA02E466)Key Project of National Natural Science Foundation of China to Huijun Yuan (No.81030017)and to Pu Dai(No.30872862)
文摘Non-syndromic low-frequency sensorineural hearing loss （LFSNHL） is an unusual type of hearing loss in which frequencies ≤2000 Hz predominantly are affected. To date, different mutations in two genes, DIAPHI and WFSI, have been found to be associated with LFSNHL. Here, we report a five-generation Chinese family with postlingual and progressive LFSNHL. We mapped the disease locus to a 2.5 Mb region on chromosome 4p16 between markers SNP_A-2167174 and D4S431, overlapping with the DFNA6/14/38 locus. Sequencing of candidate gene revealed a heterozygous c.2086C〉T substitution in exon 8 of WFS1, leading to p.H696Y substitution at the C-terminus of Wolframin （WFS 1）. In addition, we performed mutational screening of WFS1 in 37 sporadic patients, 7--50 years of age, with LFSNHL. We detected a heterozygous c.2108G〉A substitution in exon 8 of WFSI, leading to p.R703H substitution in a patient. The H696 and R703 in WFS1 are highly conserved across species, including human, orangutan, rat, mouse, and frog （Xenopus）, Sequence analysis demonstrated the absence of c.2086C〉T or c.210gG〉A substitutions in the WFS1 genes among 200 unrelated control subjects of Chinese background, supporting the hypothesis that they represent causative mutations, and not rare polymorphisms. Our data provide additional molecular and clinical information for establishing a better genotype-phenotype correlation for LFSNHL.
文摘X-ray diffraction (XRD), ball-disc friction and wearing machine and draw-bead test were introduced to investigat the strcusture and workability of IF sheet steel electrogalvanized deposits prepared from sulphate solution system. It was shown that the picking-up of the zinc coating on die strengthened with the increasing of friction factor which was originally affected by the coating's structure. Duing forming, (00X) planes (X= 2, 4) preferential orientation of zinc deposits increased, which resulted in enhanc ing the coating's friction behaviors. Therefore, the forming mechanism of electrogalvedzed deposit was demonstrated that both friction and the stricking -up behaviors of the coating are intensified simultaneously and affect each other.
