Publications (28)32.86 Total impact
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Article: [Comparative analysis of the recurrent mutations between Uigur and Han ethnic deaf group in Xinjiang region of China].
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ABSTRACT: To investigate the recurrent mutations between Uigur and Han ethnic deaf group in Xinjiang region and determine the relationship between ethnicity and mutations. DNA were extracted from peripheral blood of 125 deaf patients from Urumqi and Korla special educational schools in Xinjiang. Audiologic examinations showed that all patients had severe to profound bilateral sensorineural hearing hoss. The coding region of GJB2 gene, SLC26A4 and mitochondrial DNA target fragments were amplified by polymerase chain reaction (PCR). Mutations in GJB2 gene, SLC26A4IVS7-2 A>G, mtDNA 1494C>T and mtDNA1555 A>G were identified by sequencing analysis. Allelic Frequency of the GJB2 35delG and SLC26A4IVS7-2 A>G mutations in Han deaf students were 7.4% and 10.1%, respectively, whereas not found in Uigur deaf groups. The difference was statistically significant. We did not find significant differences in GJB2 235 delC, 299-300delAT, mtDNA A1555G and C1494T allelic frequency between Uigur and Han students. Prevalence of the recurrent mutations between Uigur and Han ethnic deaf group in Xinjiang has a great diversity.Lin chuang er bi yan hou ke za zhi = Journal of clinical otorhinolaryngology 01/2010; 24(1):11-5. -
Article: [Molecular etiology of non-syndromic hearing impairment in a Chinese family].
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ABSTRACT: To investigate the molecular etiology of non-syndromic hearing impairment in two patients in a maternal inherited deafness Chinese family. Peripheral blood specimens were collected and DNA templates extracted. The complete mitochondrial genomes and GJB2 gene were sequenced in an ABI 3100 Avant sequencer. The proband (III-5) and her elder sister (III-1) were found to carry the mtDNA 12SrRNA C1494T mutation. The GJB2 gene showed no mutations. The proband had the history of using aminoglycosides before hearing loss, and exhibited severe sensorineural hearing impairment; the proband's sister had no history of using aminoglycosides, and showed moderate sensorineural hearing impairment. The molecular etiology of each individual patient in a family yaries with individual genetic background.Zhonghua yi xue za zhi 09/2009; 89(36):2540-3. -
Article: Mitochondrial haplotype and phenotype of 13 Chinese families may suggest multi-original evolution of mitochondrial C1494T mutation.
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ABSTRACT: Mutations in mitochondrial DNA (mtDNA) are associated with sensorineural hearing loss. In this study, we traced the origin of the 12S rRNA C1494T mutation through analysis of the clinical, genetic, and molecular characteristics of 13 Han Chinese pedigrees with aminoglycoside-induced and non-syndromic bilateral hearing loss that were selected by C1494T screening in 3133 subjects with non-syndromic hearing impairment from 27 regions of China (13/3133). Clinical evaluation revealed the variable phenotypes of hearing impairment including severity, age-of-onset, and audiometric configuration in these subjects. Through the whole mitochondrial genome DNA sequence analysis, we identified two evolutionarily conservative variants in protein-coding genes: tRNA(Ala) T 5628C and tRNA(Tyr) A5836G mutations. However, the pedigrees with these mutations did not have a higher or lower penetrance of deafness than in other pedigrees. These results suggested that both T 5628C and A5836G mutations might not significantly modify the manifestation of the C1494T mutation. Sequencing analysis of the whole mitochondrial genome of the probands showed that 13 pedigrees from seven different provinces were classified into 10 haplogroups by the distinct sets of mtDNA polymorphisms, including haplogroups A, B, D, D4, D4b2, F1, M, M7c, N9a1, and H2b. This result suggested that the C1494T mutation occurred sporadically with multi-origins through the evolution of the mtDNA in China, and these mtDNA haplogroup-specific variants may not play an important role in the phenotypic expression of the C1494T mutation in these Chinese families with different penetrance of hearing loss. In addition, the lack of a significant mutation in the GJB2 gene ruled out the possible involvement of GJB2 in the phenotypic expression of the C1494T mutation in those affected subjects. Therefore, the aminoglycosides is solo well-established factor to contribute to the deafness manifestation of the C1494T mutation, and prevention by avoiding the administration of aminoglycosides in individuals carrying C1494T mutation is the most effective way to protect their vulnerability to deafness.Mitochondrion 09/2009; 9(6):418-28. · 3.62 Impact Factor -
Article: Distinct and novel SLC26A4/Pendrin mutations in Chinese and U.S. patients with nonsyndromic hearing loss.
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ABSTRACT: Mutations of the human SLC26A4/PDS gene constitute the most common cause of syndromic and nonsyndromic hearing loss. Definition of the SLC26A4 mutation spectrum among different populations with sensorineural hearing loss is important for development of optimal genetic screening services for congenital hearing impairment. We screened for SLC26A4 mutations among Chinese and U.S. subjects with hearing loss, using denaturing HPLC (DHPLC) and direct DNA sequencing. Fifty-two of 55 Chinese subjects with deafness accompanied by enlargement of the vestibular aqueduct (EVA) exhibited at least one mutant SLC26A4 allele, whereas SLC26A4 mutations were found in only 2 of 116 deaf Chinese patients without EVA. The spectrum of SLC26A4 mutations differed among Chinese and U.S. subjects and included 10 previously unreported SLC26A4 variants: 4 in the Chinese population (p.E303Q, p.X329, p.X467, p.X573) and 6 in the U.S. population (p.V250A, p.D266N, p.F354S, p.D697A, p.K715N, p.E737D). Among the seven novel in-frame missense mutations, five encoded SLC26A4 proteins with substantially reduced Cl(-)/anion exchange activity as expressed and measured in Xenopus oocytes, but four of these were sufficiently active to allow study of anion selectivity. The only mutant polypeptide exhibiting complete loss of anion exchange function, p.E303Q, was expressed at or near the oocyte surface at near-wild-type levels. Two variants, p.F354S and p.E737D, displayed selective reduction in relative rate of Cl(-)/HCO(3)(-) exchange compared with similarly measured rates of Cl(-)/Cl(-) and Cl(-)/I(-) exchange. Our data show that mutation analysis of the SLC26A4 gene is of high diagnostic yield among subjects with deafness and bilateral EVA in both China and the U.S. However, the pathogenicity of monoallelic SLC26A4 gene variants in patients with hearing loss remains unclear in many instances.Physiological Genomics 07/2009; 38(3):281-90. · 2.73 Impact Factor -
Article: GJB2 mutation spectrum in 2,063 Chinese patients with nonsyndromic hearing impairment.
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ABSTRACT: Mutations in GJB2 are the most common molecular defects responsible for autosomal recessive nonsyndromic hearing impairment (NSHI). The mutation spectra of this gene vary among different ethnic groups. In order to understand the spectrum and frequency of GJB2 mutations in the Chinese population, the coding region of the GJB2 gene from 2063 unrelated patients with NSHI was PCR amplified and sequenced. A total of 23 pathogenic mutations were identified. Among them, five (p.W3X, c.99delT, c.155_c.158delTCTG, c.512_c.513insAACG, and p.Y152X) are novel. Three hundred and seven patients carry two confirmed pathogenic mutations, including 178 homozygotes and 129 compound heterozygotes. One hundred twenty five patients carry only one mutant allele. Thus, GJB2 mutations account for 17.9% of the mutant alleles in 2063 NSHI patients. Overall, 92.6% (684/739) of the pathogenic mutations are frame-shift truncation or nonsense mutations. The four prevalent mutations; c.235delC, c.299_c.300delAT, c.176_c.191del16, and c.35delG, account for 88.0% of all mutantalleles identified. The frequency of GJB2 mutations (alleles) varies from 4% to 30.4% among different regions of China. It also varies among different sub-ethnic groups. In some regions of China, testing of the three most common mutations can identify at least one GJB2 mutant allele in all patients. In other regions such as Tibet, the three most common mutations account for only 16% the GJB2 mutant alleles. Thus, in this region, sequencing of GJB2 would be recommended. In addition, the etiology of more than 80% of the mutant alleles for NSHI in China remains to be identified. Analysis of other NSHI related genes will be necessary.Journal of Translational Medicine 05/2009; 7:26. · 3.41 Impact Factor -
Article: Mutations at position 7445 in the precursor of mitochondrial tRNA(Ser(UCN)) gene in three maternal Chinese pedigrees with sensorineural hearing loss.
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ABSTRACT: We report here the clinical, genetic and molecular characterization of three Chinese pedigrees with nonsyndromic bilateral hearing loss. Clinical and genetic evaluations revealed the variable severity and age-of-onset in hearing impairment in these families. Strikingly, there were extremely low penetrances of hearing impairment in these Chinese families. Sequence analysis of the complete mitochondrial DNA (mtDNA) showed the known A7445C mutation in two pedigrees and the novel A7445T mutation in another pedigree, in addition to distinct sets of mtDNA polymorphisms belong to Asian haplogroups D4j and F4. Indeed, the A7445C or A7445T mutation in the CO1 and the precursor of tRNA(Ser(UCN)) genes was present in homoplasmy only in the maternal lineage of those pedigrees but not other members of these families and 164 Chinese controls. In fact, the A7445C or A7445T mutation results in a read-through of the stop condon AGA of the CO1 message on the H strand of mtDNA, thereby adding three amino acids (Ser-Gln-Lys) to the C-terminal of the polypeptide. However, the mutated polypeptide may retain a partial function. Alternatively, the A7445C or A7445T mutation is adjacent to the site of 3' end endonucleolytic processing of L-strand RNA precursor, spanning tRNA(Ser(UCN)) and ND6 mRNA. Thus, the A7445C or A7445T mutation may also cause a defect in the processing of the L-strand RNA precursor, thus causing mitochondrial dysfunctions. Furthermore, the occurrence of the mutations at position 7445 in these genetically unrelated subjects affected by hearing impairment strongly indicates that mutations at the position 7445 are involved in the pathogenesis of hearing impairment.Mitochondrion 09/2008; 8(4):285-92. · 3.62 Impact Factor -
Article: SLC26A4 c.919-2A>G varies among Chinese ethnic groups as a cause of hearing loss.
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ABSTRACT: Mutations in the SLC26A4 gene are second only to GJB2 mutations as a currently identifiable genetic cause of sensorineural hearing loss. In most areas of China, genetic testing for sensorineural hearing loss is unavailable because of limited knowledge of the mutation spectrum. Although SLC26A4 c.919-2A>G (IVS7-2A>G) is a common mutation among some Asian populations, the mutation prevalence among various ethnic groups within China has not been studied. DNA specimens from 3271 subjects with moderate to profound sensorineural hearing loss from 27 regions of China were genotyped for the c.919-2A>G mutation by polymerase chain reaction/restriction-fragment-length polymorphism. Normal hearing controls from Han (n = 185) and Uigur (n = 152) populations were also tested. Overall, 408 subjects with sensorineural hearing loss (12.5%) carried at least one c.919-2A>G allele, with 158 (4.8%) homozygotes and 250 (7.6%) heterozygotes. Within the subpopulations examined, the rate varies from 0% to 12.2% for c.919-2A>G homozygotes and from 0% to 17.6% for heterozygotes. Based on this cohort, Chinese subjects with sensorineural hearing loss seem to have a relatively higher c.919-2A>G frequency than that of other Asian populations. These results demonstrate that a simple and efficient genetic test for the c.919-2A>G mutation alone would identify the molecular cause in up to 8-12% of individuals with sensorineural hearing loss in a few eastern and central regions of China. Those who are negative for the c.919-2A>G mutation would be candidates for further mutational analysis of SLC26A4 or other deafness-related genes. This would greatly improve genetic diagnosis and counseling for a huge number of Chinese individuals and family members with sensorineural hearing loss in China, and many more ethnic Chinese in other countries, which might be up to one million.Genetics in medicine: official journal of the American College of Medical Genetics 08/2008; 10(8):586-92. · 3.92 Impact Factor -
Article: [Features of nationwide distribution and frequency of a common gap junction beta-2 gene mutation in China].
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ABSTRACT: To determine the prevalence of a common GJB2 mutation in a big Chinese population of deaf children and the features of its distribution in regions all over the nation and to provide epidemiology data and expertise for genetic testing of deafness in China. The DNA samples of NSHI patients and normal controls were collected from different typical areas of China. The method of polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) with ApaI was used to determine the genotype of GJB2 235 site. Totally 16.3% of patients carried at least one 235 delC mutant allele. Among them, 7.8% was homozygous and 8.5% was heterozygous. The prevalence of GJB2 235delC mutation in China was evident, and the significant difference of 235delC mutation frequency was found in sub-population from different areas and different ethnic groups. Based upon the result of this screening as stated, Chinese NSHI patients appear to have 235delC frequency and the number of GJB2 related deafness was estimated to be huge. The testing of GJB2 235delC mutation would play an important role in genetic diagnosis and screening in China. As high as 15% of patients could be diagnosed as GJB2 caused deafness (bi-allelic mutation) only by means of this simple, fast and economic assay. In addition, patients were negative for 235delC mutation would be candidates for further mutational analysis of GJB2 or other deafness related genes.Zhonghua er bi yan hou tou jing wai ke za zhi = Chinese journal of otorhinolaryngology head and neck surgery 12/2007; 42(11):804-8. -
Article: [Frequency of SLC26A4 IVS7-2A > G mutation in patients with severe to profound hearing loss from different area and ethnic group in China].
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ABSTRACT: To carry out molecular epidemiology study of SLC26A4 IVS7-2 A > G mutation in large Chinese deaf population and to provide evidence for fast screening and gene diagnosis of enlarged vestibular aqueduct syndrome (EVAS). A total of 1979 patients with non-syndromic hearing loss(NSHL) underwent questionnaire and PCR for IVSA > G mutation detection of SLC26A4 gene. All 245 patients (12.38%) with homozygotes and heterozygotes IVS7-2 A > G mutation were found among the 1979 NSHL It showed statistically significant difference among north and northeast, northwest, east and southeast, southwest and central area in China. (chi2 = 34.4899, P < 0.05). Carrier frequency of the central area (27.52%) was notably higher than southwest area (6.69%). The IVS7-2 A > G mutation was most frequently found in Han deaf groups (13.88%). Tibetan, Hui, and other western minorities were lower than Han deaf population (chi2 = 35.4456, P < 0.05). A high SLC26A4 IVS7-2 A > G mutation frequency for deafness in Chinese patients was found. Detection of the pathogenic mutations was bringing the possibility to detect EVAS at an early stage. Moreover, it might help to establish diverse diagnostic strategies toward differently ethical deaf population in different region of China.Zhonghua er bi yan hou tou jing wai ke za zhi = Chinese journal of otorhinolaryngology head and neck surgery 12/2007; 42(12):893-7. -
Article: [Mutation screening of the COCH gene in familial and sporadic patients with late onset nonsyndromic sensorineural hearing loss among Chinese population].
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ABSTRACT: To investigate the mutational of the coagulation factor C homology (COCH) gene related to autosomal dominant sensorineural nonsyndromic hearing loss (DFNA) with late onset in Chinese population. Peripheral blood samples were collected from he members of 26 DFNA families, members of 19 small DFNA families with un recognized inheritance pattern, and 22 sporadic patients with sensorineural nonsyndromic late onset hearing loss, the hearing loss of all of which occurred during the age range 10 - 40, and 100 normal controls. From different parts of China, these subjects underwent questionnaire survey too. Genomic DNA was isolated, COCH mutation was screened by PCR and sequencing, and restriction endonuclease analysis was used to detect the mutation sites of the COCH gene. The conservation in evolution of the target amino acid sequences was analyzed using CluatalX1.82 software. DNA sequencing of coding regions and exon/intron boundaries of COCH 2 - 12 exons identified a heterozygous G-to-A substitution at position 1625 in exon 12 in a large DFNA family, leading to a C542Y substitution, and a heterozygous T-to-C substitution at position 1535 in exon 12 in a small family, leading to a M512T substitutions. Both the residues of Cys542 and M512 were conserved across human, mouse, chicken, and zebrafish. These mutations were not detected in the 100 control subjects. The C542Y and the M512T mutations cause hearing loss in Chinese DFNA families.Zhonghua yi xue za zhi 12/2007; 87(44):3107-10. -
Article: [Prevalence of GJB2 mutations in Uigur and Han ethnic populations with deafness in Xinjiang region of China].
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ABSTRACT: To investigate the prevalence of GJB2 mutations in Uigur and Han ethnic groups in Xinjiang Uigur Autonomous Region, China and to understand the mutation spectrum and frequency of the GJB2 gene in these 2 ethnic groups. Questionnaire survey was conducted among 61 Uigur deaf-mute students, 60 Han deaf-mute students, and 98 normal Uigurs and 301 normal Han people as controls. Peripheral blood samples were collected to undergo PCR and sequencing of GJB2 gene. The GJB2 mutation rate of the Uigur deaf-mute students was 19.7%, not significantly different from that of the Han deaf-mute students (17.2%). GJB2 35delG was found only in the Uigur deaf-mutes with a carrier rate of 11.5%, whereas 235delC was identified in both Uigur and Han deaf-mutes. The allelic frequency of 35delG mutation in the Uigur and Han deaf-mutes and the Uigur controls were 7.4% (9/122), 0 (0/128), and 0 (0/196) respectively. The allelic frequencies of the GJB2 235delC mutations in the Uigur and Han deaf-mute students were 5.7% and 9.8%, and the allelic frequencies of 299 - 300delAT were 0.8% and 5.5%. V27I and E114G were the most frequent types of polymorphism. There is a rather high mutation rate of GJB2 gene in Xinjiang. The carrier frequency of 35delG of the Uigurs is significantly higher than that of the Han population. 235delC is common in both Uigur and Han people.Zhonghua yi xue za zhi 12/2007; 87(42):2977-81. -
Article: Coexistence of mitochondrial 12S rRNA C1494T and CO1/tRNA(Ser(UCN)) G7444A mutations in two Han Chinese pedigrees with aminoglycoside-induced and non-syndromic hearing loss.
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ABSTRACT: Mutations in mitochondrial DNA are one of the important causes of hearing loss. We report here the clinical, genetic, and molecular characterization of two Han Chinese pedigrees with maternally transmitted aminoglycoside-induced and nonsyndromic bilateral hearing loss. Clinical evaluation revealed the wide range of severity, age-at-onset, and audiometric configuration of hearing impairment in matrilineal relatives in these families. The penetrances of hearing loss in these pedigrees were 20% and 18%, when aminoglycoside-induced deafness was included. When the effect of aminoglycosides was excluded, the penetrances of hearing loss in these seven pedigrees were 10% and 15%. Sequence analysis of the complete mitochondrial genomes in these pedigrees showed the presence of the deafness-associated 12S rRNA C1494T and CO1/tRNA(Ser(UCN)) G7444A mutations. Their distinct sets of mtDNA polymorphism belonged to Eastern Asian haplogroup C4a1, while other previously identified six Chinese mitochondrial genomes harboring the C1494T mutation belong to haplogroups D5a2, D, R, and F1, respectively. This suggested that the C1494T or G7444A mutation occurred sporadically and multiplied through evolution of the mitochondrial DNA (mtDNA). The absence of functionally significant mutations in tRNA and rRNAs or secondary LHON mutations in their mtDNA suggest that these mtDNA haplogroup-specific variants may not play an important role in the phenotypic expression of the 12S rRNA C1494T and CO1/tRNA(Ser(UCN)) G7444A mutations in those Chinese families. However, aminoglycosides and other nuclear modifier genes play a modifying role in the phenotypic manifestation of the C1494T mutation in these Chinese families.Biochemical and Biophysical Research Communications 11/2007; 362(1):94-100. · 2.48 Impact Factor -
Article: [Mutation of GJB2 gene in nonsyndromic hearing impairment patients: analysis of 1190 cases].
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ABSTRACT: To analyze the sequence of GJB2 gene in nonsyndromic hearing impairment (NSHI) patients in China. Peripheral blood samples were obtained from 1190 NSHI patients randomly selected from the Deaf and Mute Schools of Beijing, Hebei, Heilongjiang, Jilin, Inner Mongolia, Shanxi, Henan, Hubei, Shaanxi, Gansu, Ningxia, Qinghai, Anhui, Jiangsu, Shanghai, Fujian, Guangdong, and Guangxi, and 301 children with normal hearing level used as controls. Genomic DNA was extracted by extraction kits to undergo polymerase chain reaction and sequencing so as to detect the mutations of GJB2 gene. Sixteen pathogenic mutations of GJB2 gene were found, the most common of which included 235delC, 299-300delAT, and 176del16bp. 250 patients (21.05%) carried definite GJB2 mutations, 245 of which (98%) carried at least one of these 3 common mutations. 222 of the 250 patients (88.80%) carried the mutation 235delC with a detection rate of 18.66%. 62 of the 250 patients (24.80%) carried the mutation 299-300delAT with a detection rate of 5.21%. 19 of the 250 patients (7.60%) carried the mutation 176del16bp with a detection rate of 1.60%. The detection rates of these 3 mutations in the NSHI patients were all significantly higher than those among the controls (all P<0.01). The hot spot of GJB2 gene mutations in Chinese NSHI patients is 235delC, followed by 299-300delAT and 176del16bp. These results establish a fundamental basis for drawing a spectrum of GJB2 gene mutation among Chinese population.Zhonghua yi xue za zhi 10/2007; 87(40):2814-9. -
Article: [Sequencing of SLC26A4 exons 7 and 8 and hot spot mutation analysis in 1552 moderate to profound sensorineural hearing loss patients in China].
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ABSTRACT: To investigate the hot spot mutation of SLC26A4 gene and its incidence among patients with moderate to profound sensorineural hearing loss (SNHL) and to analyze the epidemiology of enlarged vestibular aqueduct syndrome in China. Peripheral blood samples were collected from 1,552 students of deaf and dumb school in 21 cities throughout China. The nationality distribution of the 1,552 students included Han (n = 1290), Uigur (n = 69), Hui (n = 37), Mongolian (n = 31), and Southwest minorities including Yi, Zhuang, Bai, Miao and other 14 nationalities (n = 125). The hot spot mutation IVS7-2A > G and other mutations in the SLC26A4 exons 7 and 8 with intron 7 were analyzed by direct sequencing. Mutation in the SLC26A4 exons 7 and 8 or intron 7 were found in 199 students, of whom 83 carried IVS7-2A > G homozygous mutation, 114 carried IVS7-2A > G heterozygous mutation, and the other two carried two other kinds of mutation. Of the 1,552 cases, the percentage of cases carrying IVS7-2A > G mutation was 12.7% (197/1,552), and this percentage reached up to 14.3% in 1,290 cases of Han nationality, while in the 69 cases of Uigur nationality this ratio was 0. The prevalence rates of IVS7-2A > G mutation in Zhuozhou and Gaobeidian, Hebei province, and Anyang, Henan province, were 24.7% and 28.3% respectively, both significantly higher than the percentages of the whole China and other regions (all P < 0.05). Hereditary SNHL caused by SLC26A4 mutations accounts for a high percentage in China. It is of great importance to screen SLC26A4 gene for making etiological diagnosis for deafness. Screening of the hot spot mutation of IVS7-2A > G is of advantage for large scale screening among patients with deafness.Zhonghua yi xue za zhi 10/2007; 87(36):2521-5. -
Article: [Audiological and vestibular evaluation of new coagulation factor C homology mutation carriers in a Chinese family].
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ABSTRACT: To analyze the clinical features of audiological and vestibular function in a Chinese family with late onset autosomal dominant nonsyndromic sensorineural hearing loss. Comprehensive audiological and vestibular evaluation including pure tone audiometry, auditory brainstem response (ABR), electrocochleogram (EcochG), oculomotor testing, caloric tests, rotational testing, computerized dynamic posturography and vestibular evoked myogenic potentials (VEMP) were conducted to identify the hearing and vestibular impairment. All affected family members shared sensorineural hearing loss with full penetrance starting between the second and fifth decade of life as a high frequency loss which progresses to a severe to profound loss at the sixth to seventh decade. The extensive vestibular evaluation indicated that all affected members performed normally in computerized dynamic posturography and caloric testing. Impairment of the saccular otolith in all of six affected members was suggested by results of the VEMP test. The velocity step test generated abnormal time constants and sinusoidal oscillation test generated abnormal gains and phase in affected members indicated that horizontal canal vestibular hyporeflexia in history. All affected subjects examined in this family showed completely normal ocular motor responses in oculomotor testing, including smooth pursuit, optokinetic nystagmus, gaze and saccade. The predominant feature of the Chinese DFNA9 family was that all the affected subjects harboring COCH mutation in the vWFA2 domain didn't suffer the vestibular symptoms during their life time and comprehensive vestibular assessment revealed only subtle vestibular hypofunction in affected members of this family. There is a genotype-phenotype correlation in DFNA9.Zhonghua er bi yan hou tou jing wai ke za zhi = Chinese journal of otorhinolaryngology head and neck surgery 09/2007; 42(8):594-8. -
Article: The mitochondrial tRNA(Ala) T5628C variant may have a modifying role in the phenotypic manifestation of the 12S rRNA C1494T mutation in a large Chinese family with hearing loss.
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ABSTRACT: We report here the clinical, genetic, and molecular characterization of a large Han Chinese family with aminoglycoside-induced and nonsyndromic hearing loss. Two and 13 of 66 matrilineal relatives suffered from aminoglycoside-induced and nonsyndromic hearing loss, respectively. These matrilineal relatives exhibited a wide range of severity of hearing loss, varying from profound to normal hearing. In the absence of aminoglycosides, the age-at-onset of hearing impairment in these matrilineal relatives ranged from 13 to 50years. Furthermore, these affected matrilineal relatives shared some common features: bilateral hearing loss of high frequencies and symmetries. Sequence analysis of mitochondrial DNA (mtDNA) in the pedigree identified the homoplasmic 12S rRNA C1494T mutation and other 34 variants belonging to Eastern Asian haplogroup F1. Of these, the variant T5628C occurs at an extremely conserved nucleotide (A31) of tRNA(Ala). This variant converted a very conservative A-U to a G-U base-pairing at AC-stem of this tRNA. The disruption of this base-pairing in tRNAs by mtDNA mutations has been associated with several clinical abnormalities. The alteration of structure of the tRNA(Ala) by the T5628C mutation may lead to a failure in tRNA metabolism and lead to impairment of mitochondrial translation, thereby worsening mitochondrial dysfunctions, caused by the C1494T mutation. Therefore, this mtDNA mutation may influence the phenotypic manifestation of the 12S rRNA C1494T mutation in this Chinese pedigree.Biochemical and Biophysical Research Communications 07/2007; 357(2):554-60. · 2.48 Impact Factor -
Article: The prevalence of the 235delC GJB2 mutation in a Chinese deaf population.
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ABSTRACT: Mutations in the GJB2 gene are the most frequently found mutations in patients with nonsyndromic hearing impairment in populations studied to date. However, the prevalence of mutations varies among different ethnic groups. In most areas of China, genetic testing for nonsyndromic hearing impairment is currently not available because of the lack of information regarding the molecular cause of nonsyndromic hearing impairment. The purpose of this study is to determine the prevalence of a common GJB2 mutation, 235delC, in Chinese deaf children. We collected DNA specimens from 3004 patients with nonsyndromic hearing impairment from 26 regions of China; 368 Han Chinese and 98 Uigur controls, and screened for the 235delC mutation. The coding exon of the GJB2 gene was polymerase chain reaction amplified, followed by restriction enzyme digestion with ApaI and analysis by agarose gel. Overall, 488 patients (16.3%) were determined to carry at least one 235delC mutant allele, with 233 (7.8%) homozygotes and 255 (8.5%) heterozygotes. Therefore, within the subpopulations examined, the frequency varies from 0% to 14.7% for 235delC homozygotes and from 1.7% to 16.1% for heterozygotes. On the basis of this survey of the patient cohort as stated, Chinese patients with nonsyndromic hearing impairment appear to have a relatively higher 235delC frequency than that of other Asian populations. These results demonstrate that an easy and fast genetic testing method for this well-known GJB2 gene mutation can be made available for at least 2 million Chinese patients and family members with nonsyndromic hearing impairment. By screening for the common GJB2 235delC mutation, the molecular cause in as high as 15% of patients with nonsyndromic hearing impairment in certain regions of China can be identified. In addition, patients who are negative for the 235delC mutation would be candidates for further mutational analysis of GJB2 or other deafness-related genes.Genetics in Medicine 06/2007; 9(5):283-9. · 4.76 Impact Factor -
Article: [Molecular etiology of 573 patients with nonsyndromic hearing loss in 5 provinces of northwest region of China].
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ABSTRACT: To analyze the prevalence of an A-to-G mutation at nucleotide 1555 of the mitochondrial genome in patients with nonsyndromic hearing impairment (NSHI) of northwest region of China. A standardized program of epidemiological design, administrative support, sample collection and mutation screening for mtDNA 12SrRNA A1555G were used performed to study the general condition and the molecular etiology of patients with severe to profound hearing loss from 5 provinces of northwest region of China. Five-hundred-seventy-three cases with severe profound hearing loss from 5 provinces were collected and 31 cases were found to carry mtDNA 12SrRNA A1555G mutation. Among the patients with severe to profound hearing loss from 5 provinces of northwest region, there was a high proportion of hereditary hearing impairment caused by mtDNA 12SrRNA A1555G mutation. Screening and testing for this mutation are effective methods to prevent ototoxicity in A1555G carriers and their maternal family members.Lin chuang er bi yan hou ke za zhi = Journal of clinical otorhinolaryngology 06/2007; 21(10):460-2. -
Article: [Genetic counseling and intervention for families with deaf-mute patients based on genetic testing: analysis of 5 families].
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ABSTRACT: To analyze the molecular genetic mechanisms of pathogenesis of deafness in the families with deaf-mute patients and analyze the strategies of genetic counseling and intervention for these families. Peripheral blood samples were collected from the probands with deaf-muteness and their parents of five families and genetic tests were conducted to analyze the GJB2, SLC26A4 (PDS), and mitochondrial DNA (mtDNA) A 1555G genes for the existence of mutation. Families 1-3 had one child with hearing loss each while the parents had normal hearing and the mothers had been pregnant for 6-18 weeks. Both parents of family 4 were deaf-mute, and the wife of family 5 was deaf-mute while her husband had normal hearing. The proband from family 1 was proven to carry compound GJB2 mutations while his parents carried a single GJB2 mutation; prenatal testing showed that the fetus only carried the paternal mutation. The proband from family 2 was proven to carry compound SLC26A4 (PDS) mutations while his parents carried a single SLC26A4 (PDS) mutation; prenatal testing showed that the fetus only carried the paternal mutation. The proband from family 3 and his parents didn't carry any GJB2, SLC26A4 and mtDNA A1555G mutation. Observation showed that the new born babies of these three families all had normal hearing revealed by new born hearing screening and ABR test. The husband from family 4 was homozygous GJB2 235delC while his wife was mtDNA A1555G positive. This couple was advised to strictly avoid the administration of aminoglycoside antibiotics to their future offspring. In family 5, the wife carried compound SLC26A4 (PDS) mutations while her husband carried a single SLC26A4 (PDS) mutation; and they were told about the 50% risk of their offspring's suffering from enlarged vestibular aqueduct syndrome. Genetic testing with prenatal testing and relevant intervention for the families with deaf-mute patients can be applied to prevent another deaf-mute member from being born.Zhonghua yi xue za zhi 05/2007; 87(16):1088-92. -
Article: Nonsense mutations in the PAX3 gene cause Waardenburg syndrome type I in two Chinese patients.
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ABSTRACT: Waardenburg syndrome type I (WS1) is an autosomal dominant disorder characterized by sensorineural hearing loss, pigmental abnormalities of the eye, hair and skin, and dystopia canthorum. The gene mainly responsible for WS1 is PAX3 which is involved in melanocytic development and survival. Mutations of PAX3 have been reported in familiar or sporadic patients with WS1 in several populations of the world except Chinese. In order to explore the genetic background of Chinese WS1 patients, a mutation screening of PAX3 gene was carried out in four WS1 pedigrees. A questionnaire survey and comprehensive clinical examination were conducted in four Chinese pedigrees of WS1. Genomic DNA from each patient and their family members was extracted and exons of PAX3 were amplified by PCR. PCR fragments were ethanol-purified and sequenced in both directions on an ABI_Prism 3100 DNA sequencer with the BigDye Terminator Cycle Sequencing Ready Reaction Kit. The sequences were obtained and aligned to the wild type sequence of PAX3 with the GeneTool program. Two nonsense PAX3 mutations have been found in the study population. One is heterozygous for a novel nonsense mutation S209X. The other is heterozygous for a previously reported mutation in European population R223X. Both mutations create stop codons leading to truncation of the PAX3 protein. This is the first demonstration of PAX3 mutations in Chinese WS1 patients and one of the few examples of an identical mutation of PAX3 occurred in different populations.Chinese medical journal 02/2007; 120(1):46-9. · 0.86 Impact Factor
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Institutions
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2010
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Nanjing Medical University
Nanjing, Jiangsu Sheng, China
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2006–2008
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Chinese PLA General Hospital
Beijing, Beijing Shi, China
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2005–2006
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307 Hospital of the Chinese People's Liberation Army
Beijing, Beijing Shi, China
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