RESUMO
The Spanish flu, Asian flu, Hong Kong flu, HIV/AIDS, SARS, Ebola, and Swine flu, among others, have had a significant impact on agriculture, education, the economy, and human activities, including leisureliness, shipping, healthiness, fisheries, mining, industry, and trade. Currently, manhood is dealing with a new epidemic, the infection of the latest coronavirus (2019-nCoV), which causes a deadly disease named COVID-19. This article aims to examine COVID-19's effect on agriculture, education, and the economy. There are existing estimates to conclude that the COVID-19 pandemic has a significant influence on agriculture and the food supply chain, mostly influencing food demand and, as a result, food security, with a disproportionate impact on the most disadvantaged. To overcome spread of COVID-19, a non-contact food delivery system has been used by utilizing drown for this purpose. This epidemic crisis also introduced a digital education system that is challenging for students and teachers who are not educated in it. Weak infrastructure, such as electricity, poor access to the Internet connection, and a lack of technology literacy, has hampered the online education system. Coronavirus has an undesirable influence on the global economy by affecting tourism, the financial market, commerce, shipping, manufacturing, and the service sector. The exchange market was also down during the COVID-19 pandemic. In conclusion, we should strictly follow SOP's to improve our agriculture, education, economy, and other ways of normal life. We should also be vaccinated to fulfill our all losses in different fields.
Assuntos
COVID-19 , Influenza Pandêmica, 1918-1919 , Agricultura , Segurança Alimentar , História do Século XX , Humanos , Pandemias , SARS-CoV-2 , Fatores SocioeconômicosRESUMO
Sugarcane (Saccharum officinarum L.) is a cash crop grown commercially for its higher amounts of sucrose, stored within the mature internodes of the stem. Numerous studies have been done for the resistance development against biotic and abiotic stresses to save the sucrose yields. Quality and yield of sugarcane production is always threatened by the damages of cane borers and weeds. In current study two problems were better addressed through the genetic modification of sugarcane for provision of resistance against insects and weedicide via the expression of two modified cane borer resistant CEMB-Cry1Ac (1.8 kb), CEMB-Cry2A (1.9 kb) and one glyphosate tolerant CEMB-GTGene (1.4 kb) genes, driven by maize Ubiquitin Promoter and nos terminator. Insect Bio-toxicity assays were carried out for the assessment of Cry proteins through mortality percent of shoot borer Chilo infuscatellus at 2nd instar larvae stage. During V0, V1 and V2 generations young leaves from the transgenic sugarcane plants were collected at plant age of 20, 40, 60, 80 days and fed to the Chilo infuscatellus larvae. Up to 100% mortality of Chilo infuscatellus from 80 days old transgenic plants of V2 generation indicated that these transgenic plants were highly resistant against shoot borer and the gene expression level is sufficient to provide complete resistance against target pests. Glyphosate spray assay was carried out for complete removal of weeds. In V1-generation, 70-76% transgenic sugarcane plants were found tolerant against glyphosate spray (3000 mL/ha) under field conditions. While in V2-generation, the replicates of five selected lines 4L/2, 5L/5, 6L/5, L8/4, and L9/6 were found 100% tolerant against 3000 mL/ha glyphosate spray. It is evident from current study that CEMB-GTGene, CEMB-Cry1Ac and CEMB-Cry2A genes expression in sugarcane variety CPF-246 showed an efficient resistance against cane borers (Chilo infuscatellus) and was also highly tolerant against glyphosate spray. The selected transgenic sugarcane lines showed sustainable resistance against cane borer and glyphosate spray can be further exploited at farmer's field level after fulfilling the biosafety requirements to boost the sugarcane production in the country.
Assuntos
Produtos Agrícolas/genética , Resistência à Doença/genética , Controle de Pragas/métodos , Plantas Geneticamente Modificadas/genética , Saccharum/genética , Animais , Produtos Agrícolas/efeitos dos fármacos , Produtos Agrícolas/parasitologia , Glicina/análogos & derivados , Glicina/farmacologia , Resistência a Herbicidas/genética , Larva , Mariposas , Proteínas de Plantas/genética , Plantas Daninhas , Plantas Geneticamente Modificadas/efeitos dos fármacos , Plantas Geneticamente Modificadas/parasitologia , Saccharum/efeitos dos fármacos , Saccharum/parasitologia , GlifosatoRESUMO
Polycomb group (PcG) and trithorax group (trxG) proteins are evolutionary conserved factors that contribute to cell fate determination and maintenance of cellular identities during development of multicellular organisms. The PcG maintains heritable patterns of gene silencing while trxG acts as anti-silencing factors by conserving activation of cell type specific genes. Genetic and molecular analysis has revealed extensive details about how different PcG and trxG complexes antagonize each other to maintain cell fates, however, the cellular signaling components that contribute to the preservation of gene expression by PcG/trxG remain elusive. Here, we report an ex vivo kinome-wide RNAi screen in Drosophila aimed at identifying cell signaling genes that facilitate trxG in counteracting PcG mediated repression. From the list of trxG candidates, Ballchen (BALL), a histone kinase known to phosphorylate histone H2A at threonine 119 (H2AT119p), was characterized as a trxG regulator. The ball mutant exhibits strong genetic interactions with Polycomb (Pc) and trithorax (trx) mutants and loss of BALL affects expression of trxG target genes. BALL co-localizes with Trithorax on chromatin and depletion of BALL results in increased H2AK118 ubiquitination, a histone mark central to PcG mediated gene silencing. Moreover, BALL was found to substantially associate with known TRX binding sites across the genome. Genome wide distribution of BALL also overlaps with H3K4me3 and H3K27ac at actively transcribed genes. We propose that BALL mediated signaling positively contributes to the maintenance of gene activation by trxG in counteracting the repressive effect of PcG.
RESUMO
Hepatitis C is an inflammatory liver disease caused by the single-stranded RNA (ssRNA) hepatitis C virus (HCV). The genetic diversity of the virus and quasispecies produced during replication have resulted in viral resistance to direct-acting antivirals (DAAs) as well as impediments in vaccine development. The recent adaptation of CRISPR-Cas as an alternative antiviral approach has demonstrated degradation of viral nucleic acids in eukaryotes. In particular, the CRISPR-effector Cas13 enzyme has been shown to target ssRNA viruses effectively. In this work, we have employed Cas13a to knockdown HCV in mammalian cells. Using a computational screen, we identified several potential Cas13a target sites within highly conserved regions of the HCV internal ribosomal entry site (IRES). Our results demonstrate significant inhibition of HCV replication as well as translation in huh-7.5 cells with minimal effects on cell viability. These findings were validated using a multi-modality approach involving qRT-PCR, luciferase assay, and MTT cell viability assay. In conclusion, the CRISPR-Cas13a system efficiently targets HCV in vitro, suggesting its potential as a programmable therapeutic antiviral strategy.
Assuntos
Proteínas Associadas a CRISPR/genética , Sistemas CRISPR-Cas , Repetições Palindrômicas Curtas Agrupadas e Regularmente Espaçadas , Marcação de Genes , Hepacivirus/genética , Hepatite C/terapia , Sítios Internos de Entrada Ribossomal , RNA Viral/genética , Proteínas Associadas a CRISPR/metabolismo , Linhagem Celular Tumoral , Hepacivirus/crescimento & desenvolvimento , Hepacivirus/metabolismo , Hepatite C/genética , Hepatite C/virologia , Humanos , Estabilidade de RNA , RNA Viral/metabolismo , Replicação Viral/efeitos dos fármacosRESUMO
BACKGROUND: Polycomb group (PcG) and trithorax group (trxG) proteins contribute to the specialization of cell types by maintaining differential gene expression patterns. Initially discovered as positive regulators of HOX genes in forward genetic screens, trxG counteracts PcG-mediated repression of cell type-specific genes. Despite decades of extensive analysis, molecular understanding of trxG action and regulation are still punctuated by many unknowns. This study aimed at discovering novel factors that elicit an anti-silencing effect to facilitate trxG-mediated gene activation. RESULTS: We have developed a cell-based reporter system and performed a genome-wide RNAi screen to discover novel factors involved in trxG-mediated gene regulation in Drosophila. We identified more than 200 genes affecting the reporter in a manner similar to trxG genes. From the list of top candidates, we have characterized Enoki mushroom (Enok), a known histone acetyltransferase, as an important regulator of trxG in Drosophila. Mutants of enok strongly suppressed extra sex comb phenotype of Pc mutants and enhanced homeotic transformations associated with trx mutations. Enok colocalizes with both TRX and PC at chromatin. Moreover, depletion of Enok specifically resulted in an increased enrichment of PC and consequently silencing of trxG targets. This downregulation of trxG targets was also accompanied by a decreased occupancy of RNA-Pol-II in the gene body, correlating with an increased stalling at the transcription start sites of these genes. We propose that Enok facilitates trxG-mediated maintenance of gene activation by specifically counteracting PcG-mediated repression. CONCLUSION: Our ex vivo approach led to identification of new trxG candidate genes that warrant further investigation. Presence of chromatin modifiers as well as known members of trxG and their interactors in the genome-wide RNAi screen validated our reverse genetics approach. Genetic and molecular characterization of Enok revealed a hitherto unknown interplay between Enok and PcG/trxG system. We conclude that histone acetylation by Enok positively impacts the maintenance of trxG-regulated gene activation by inhibiting PRC1-mediated transcriptional repression.
Assuntos
Proteínas Cromossômicas não Histona/metabolismo , Proteínas de Drosophila/metabolismo , Histona Acetiltransferases/metabolismo , Interferência de RNA , Animais , Linhagem Celular , Cromatina/metabolismo , Proteínas Cromossômicas não Histona/antagonistas & inibidores , Proteínas Cromossômicas não Histona/genética , Drosophila/citologia , Drosophila/metabolismo , Proteínas de Drosophila/antagonistas & inibidores , Proteínas de Drosophila/genética , Genes Reporter , Histona Acetiltransferases/genética , Complexo Repressor Polycomb 1/metabolismo , Ligação Proteica , Mapas de Interação de ProteínasRESUMO
Hepatitis C compromises the quality of life of more than 350 million individuals worldwide. Over the last decade, therapeutic regimens for treating hepatitis C virus (HCV) infections have undergone rapid advancements. Initially, structure-based drug design was used to develop molecules that inhibit viral enzymes. Subsequently, establishment of cell-based replicon systems enabled investigations into various stages of HCV life cycle including its entry, replication, translation, and assembly, as well as role of host proteins. Collectively, these approaches have facilitated identification of important molecules that are deemed essential for HCV life cycle. The expanded set of putative virus and host-encoded targets has brought us one step closer to developing robust strategies for efficacious, pangenotypic, and well-tolerated medicines against HCV. Herein, we provide an overview of the development of various classes of virus and host-directed therapies that are currently in use along with others that are undergoing clinical evaluation.
Assuntos
Antivirais/farmacologia , Hepacivirus/efeitos dos fármacos , Hepacivirus/genética , Animais , Antivirais/química , Antivirais/uso terapêutico , Genótipo , Hepacivirus/fisiologia , Hepatite C/tratamento farmacológico , Humanos , Resultado do Tratamento , Vacinas Virais/imunologiaRESUMO
BACKGROUND: In the present study we aimed: 1) To establish the prevalence and clinical impact of DFNB49 mutations in deaf Roma from 2 Central European countries (Slovakia and Hungary), and 2) to analyze a possible common origin of the c.1331+2T>C mutation among Roma and Pakistani mutation carriers identified in the present and previous studies. METHODS: We sequenced 6 exons of the MARVELD2 gene in a group of 143 unrelated hearing impaired Slovak Roma patients. Simultaneously, we used RFLP to detect the c.1331+2T>C mutation in 85 Hungarian deaf Roma patients, control groups of 702 normal hearing Romanies from both countries and 375 hearing impaired Slovak Caucasians. We analyzed the haplotype using 21 SNPs spanning a 5.34Mb around the mutation c.1331+2T>C. RESULTS: One pathogenic mutation (c.1331+2T>C) was identified in 12 homozygous hearing impaired Roma patients. Allele frequency of this mutation was higher in Hungarian (10%) than in Slovak (3.85%) Roma patients. The identified common haplotype in Roma patients was defined by 18 SNP markers (3.89 Mb). Fourteen common SNPs were also shared among Pakistani and Roma homozygotes. Biallelic mutation carriers suffered from prelingual bilateral moderate to profound sensorineural hearing loss. CONCLUSIONS: We demonstrate different frequencies of the c.1331+2T>C mutation in hearing impaired Romanies from 3 Central European countries. In addition, our results provide support for the hypothesis of a possible common ancestor of the Slovak, Hungarian and Czech Roma as well as Pakistani deaf patients. Testing for the c.1331+2T>C mutation may be recommended in GJB2 negative Roma cases with early-onset sensorineural hearing loss.
Assuntos
Perda Auditiva/genética , Proteína 2 com Domínio MARVEL/genética , Mutação , Polimorfismo de Nucleotídeo Único , Roma (Grupo Étnico)/genética , Idade de Início , Alelos , Conexina 26 , Conexinas , República Tcheca/etnologia , Éxons/genética , Efeito Fundador , Frequência do Gene , Genótipo , Haplótipos/genética , Perda Auditiva/congênito , Perda Auditiva/etnologia , Humanos , Hungria/etnologia , Lactente , Paquistão/etnologia , Prevalência , Homologia de Sequência do Ácido Nucleico , Eslováquia/etnologiaRESUMO
A 17-year-old boy presented to emergency department with abdominal pain in the left upper quadrant along with a palpable mass. A CT scan revealed a 10 x 8.5 cm mass in the retroperitoneal area, suggestive of a sarcoma. The patient underwent surgical resection of the lesion, the histological examination of which confirmed a paraganglioma. An 131I-Metaiodobenzylguanidine (MIBG) scan excluded distant metastasis. Paragangliomas are rare tumours of the neuroendocrine system and certain considerations are pivotal in the management of these tumours. Urinary and plasma catecholamines measurement along with CT, MRI, and MIBG scanning facilitate diagnosis, localisation and characterisation of these tumours. Surgical excision is the treatment of choice for both primary and recurrent tumours. Unfortunately, histological characterisation for malignancy is limited and these tumours are considered malignant upon development of metastasis or local recurrence. Inexistence of histological criteria for malignancy means a long-term surveillance is the norm in these patients.
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Paraganglioma/cirurgia , Neoplasias Retroperitoneais/cirurgia , Adolescente , Procedimentos Cirúrgicos do Sistema Digestório , Humanos , Masculino , Paraganglioma/diagnóstico , Neoplasias Retroperitoneais/diagnóstico , Tomografia Computadorizada por Raios X , Resultado do TratamentoRESUMO
BACKGROUND: The Drosophila GAGA factor (GAF) participates in nucleosome remodeling to activate genes, acts as an antirepressor and is associated with heterochromatin, contributing to gene repression. GAF functions are intimately associated to chromatin-based epigenetic control, linking basic transcriptional regulation to heritable long-term maintenance of gene expression. These diverse functions require GAF to interact with different partners in different multiprotein complexes. The two isoforms of GAF depict highly conserved glutamine-rich C-terminal domains (Q domain), which have been implicated in complex formation. RESULTS: Here we show that the Q domains exhibit prion-like properties. In an established yeast test system the two GAF Q domains convey prion activities comparable to well known yeast prions. The Q domains stably maintain two distinct conformational states imposing functional constraints on the fused yeast reporter protein. The prion-like phenotype can be reversibly cured in the presence of guanidine HCl or by over-expression of the Hsp104 chaperone protein. Additionally, when fused to GFP, the Q domains form aggregates in yeast cells. CONCLUSION: We conclude that prion-like behavior of the GAF Q domain suggests that this C-terminal structure may perform stable conformational switches. Such a self-perpetuating change in the conformation could assist GAF executing its diverse epigenetic functions of gene control in Drosophila.
Assuntos
Proteínas de Ligação a DNA/química , Proteínas de Ligação a DNA/metabolismo , Proteínas de Drosophila/química , Proteínas de Drosophila/metabolismo , Drosophila melanogaster/metabolismo , Peptídeos , Príons/química , Príons/metabolismo , Fatores de Transcrição/química , Fatores de Transcrição/metabolismo , Sequência de Aminoácidos , Animais , Proteínas de Ligação a DNA/genética , Proteínas de Drosophila/genética , Drosophila melanogaster/genética , Epigênese Genética , Dados de Sequência Molecular , Fenótipo , Estrutura Terciária de Proteína , Fatores de Transcrição/genéticaRESUMO
Sensorineural hearing loss is genetically heterogeneous. Here, we report that mutations in CIB2, which encodes a calcium- and integrin-binding protein, are associated with nonsyndromic deafness (DFNB48) and Usher syndrome type 1J (USH1J). One mutation in CIB2 is a prevalent cause of deafness DFNB48 in Pakistan; other CIB2 mutations contribute to deafness elsewhere in the world. In mice, CIB2 is localized to the mechanosensory stereocilia of inner ear hair cells and to retinal photoreceptor and pigmented epithelium cells. Consistent with molecular modeling predictions of calcium binding, CIB2 significantly decreased the ATP-induced calcium responses in heterologous cells, whereas mutations in deafness DFNB48 altered CIB2 effects on calcium responses. Furthermore, in zebrafish and Drosophila melanogaster, CIB2 is essential for the function and proper development of hair cells and retinal photoreceptor cells. We also show that CIB2 is a new member of the vertebrate Usher interactome.
Assuntos
Proteínas de Ligação ao Cálcio/genética , Perda Auditiva Neurossensorial/genética , Mutação , Síndromes de Usher/genética , Animais , Células COS , Proteínas de Ligação ao Cálcio/metabolismo , Chlorocebus aethiops , Drosophila melanogaster/genética , Drosophila melanogaster/crescimento & desenvolvimento , Ligação Genética , Células Ciliadas Vestibulares/metabolismo , Células Ciliadas Vestibulares/patologia , Perda Auditiva Neurossensorial/fisiopatologia , Humanos , Camundongos , Linhagem , Conformação Proteica , Relação Estrutura-Atividade , Síndromes de Usher/fisiopatologia , Peixe-Zebra/genética , Peixe-Zebra/crescimento & desenvolvimentoRESUMO
INTRODUCTION: In the United Kingdom, surgical training reforms as part of modernising medical careers (MMC) became fully operational in 2007. This study aims to establish the level of insight and views about MMC based surgical training amongst surgical trainers and trainees working in the National Health Service. METHODS: An electronic survey consisting of eight questions was disseminated to surgical trainers and trainees via a web-based link placed on Association of Surgeons in Training website. RESULTS: A total of 138 responses were received. Of those, 77% (n = 107) were from trainees. 92% (n = 127) of respondents understood that the purpose of MMC surgical reforms was to provide structured training. 98% (n = 135) agreed traditional SHO training was poorly structured. Two-thirds (67%, n = 92) believed that MMC will reduce the total time period to complete surgical training. 82% (n = 113) recognised work place assessments as an assessment tool for MMC competencies. 82% (n = 113) were aware that an educational supervisor is assigned to monitor individual training. 70% (n = 96) understood that training is a shared responsibility between trainee, educational supervisor and supervising consultants. However, 69% (n = 95) of respondents believed the standard of surgical training via MMC will deteriorate, 18% (n = 25) anticipated no difference, 8% (n = 11) passed no comments and a mere 5% (n = 7) perceived it as an improvement. CONCLUSIONS: This study confirms a generally good level of insight amongst trainers and trainees into the aims and structure of MMC based surgical training. However, the majority believe that ultimately the standard of surgical training is set to fall.
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Atitude do Pessoal de Saúde , Educação de Pós-Graduação em Medicina/normas , Cirurgia Geral/educação , Adulto , Competência Clínica , Educação de Pós-Graduação em Medicina/métodos , Educação de Pós-Graduação em Medicina/organização & administração , Feminino , Humanos , Masculino , Avaliação de Programas e Projetos de Saúde , Medicina Estatal , Inquéritos e Questionários , Reino UnidoAssuntos
Apendicectomia/educação , Cirurgia Geral/educação , Corpo Clínico Hospitalar/educação , Adolescente , Adulto , Idoso , Apendicectomia/estatística & dados numéricos , Apendicite/cirurgia , Criança , Feminino , Humanos , Masculino , Auditoria Médica , Pessoa de Meia-Idade , Reino Unido , Carga de Trabalho , Adulto JovemRESUMO
BSND encodes barttin, an accessory subunit of renal and inner ear chloride channels. To date, all mutations of BSND have been shown to cause Bartter syndrome type IV, characterized by significant renal abnormalities and deafness. We identified a BSND mutation (p.I12T) in four kindreds segregating nonsyndromic deafness linked to a 4.04-cM interval on chromosome 1p32.3. The functional consequences of p.I12T differ from BSND mutations that cause renal failure and deafness in Bartter syndrome type IV. p.I12T leaves chloride channel function unaffected and only interferes with chaperone function of barttin in intracellular trafficking. This study provides functional data implicating a hypomorphic allele of BSND as a cause of apparent nonsyndromic deafness. We demonstrate that BSND mutations with different functional consequences are the basis for either syndromic or nonsyndromic deafness.
Assuntos
Síndrome de Bartter/genética , Canais de Cloreto/genética , Surdez/genética , Mutação , Adolescente , Adulto , Audiometria , Quebra Cromossômica , Mapeamento Cromossômico , Cromossomos Humanos Par 1 , Análise Mutacional de DNA , Feminino , Ligação Genética , Marcadores Genéticos , Haplótipos , Homozigoto , Humanos , Masculino , Repetições de Microssatélites , Pessoa de Meia-Idade , Linhagem , Polimorfismo de Nucleotídeo Único , Adulto JovemRESUMO
Pendred's syndrome (PDS) is an autosomal-recessive disorder characterized by sensorineural hearing loss and goiter. PDS is caused by mutations of the SLC26A4 gene encoding pendrin, a transmembrane exchanger of Cl(-), I(-) and HCO(3)(-), which is expressed in the thyroid and inner ear. SLC26A4 mutations can also be associated with non-syndromic deafness, DFNB4. The goal of our study was to define the identities and frequencies of SLC26A4 mutations in 563 large, consanguineous Pakistani families segregating severe-to-profound recessive deafness. Sequence analyses of SLC26A4 in 46 unreported families segregating deafness linked to DFNB4/PDS revealed 16 probable pathogenic variants, 8 of which are novel. The novel variants include three missense substitutions (p.R24L, p.G139V and p.V231M), two splice site mutations (c.304+2T>C and c.1341+3A>C), one frameshift (p.C565MfsX8) and two different genomic deletions affecting exons 1-2 and 11-18. Each of six pathogenic variants (p.V239D, p.Q446R, p.S90L, p.Y556C, p.R24L and p.K715N) was found in more than one family and haplotype analyses suggest that they are founder mutations. Combined with earlier reported data, SLC26A4 mutations were identified in 56 (7.2%; 95% CI: 5.6-9.2%) of 775 families. Therefore, SLC26A4 mutations are the most common known cause of genetic deafness in this population. As p.V239D (30%), p.S90L (18%) and p.Q446R (18%) account for approximately two-third of the mutant alleles of SLC26A4, hierarchical strategies for mutation detection would be feasible and cost-efficient genetic tests for DFNB4 deafness and PDS in Pakistanis.
Assuntos
Anormalidades Múltiplas/genética , Surdez/complicações , Surdez/genética , Predisposição Genética para Doença , Proteínas de Membrana Transportadoras/genética , Mutação/genética , Sequência de Aminoácidos , Estudos de Casos e Controles , Cromossomos Humanos Par 7/genética , Éxons/genética , Haplótipos/genética , Homozigoto , Humanos , Proteínas de Membrana Transportadoras/química , Repetições de Microssatélites/genética , Dados de Sequência Molecular , Paquistão/etnologia , Mapeamento Físico do Cromossomo , Polimorfismo de Nucleotídeo Único/genética , Alinhamento de Sequência , Transportadores de Sulfato , SíndromeRESUMO
Mutations of PCDH15, encoding protocadherin 15, can cause either combined hearing and vision impairment (type 1 Usher syndrome; USH1F) or nonsyndromic deafness (DFNB23). Human PCDH15 is reported to be composed of 35 exons and encodes a variety of isoforms with 3-11 ectodomains (ECs), a transmembrane domain and a carboxy-terminal cytoplasmic domain (CD). Building on these observations, we describe an updated gene structure that has four additional exons of PCDH15 and isoforms that can be subdivided into four classes. Human PCDH15 encodes three alternative, evolutionarily conserved unique cytoplasmic domains (CD1, CD2 or CD3). Families ascertained on the basis of prelingual hearing loss were screened for linkage of this phenotype to markers for PCDH15 on chromosome 10q21.1. In seven of twelve families segregating USH1, we identified homozygous mutant alleles (one missense, one splice site, three nonsense and two deletion mutations) of which six are novel. One family was segregating nonsyndromic deafness DFNB23 due to a homozygous missense mutation. To date, in our cohort of 557 Pakistani families, we have found 11 different PCDH15 mutations that account for deafness in 13 families. Molecular modeling provided mechanistic insight into the phenotypic variation in severity of the PCDH15 missense mutations. We did not find pathogenic mutations in five of the twelve USH1 families linked to markers for USH1F, which suggest either the presence of mutations of yet additional undiscovered exons of PCDH15, mutations in the introns or regulatory elements of PCDH15, or an additional locus for type I USH at chromosome 10q21.1.
Assuntos
Caderinas/genética , Perda Auditiva/genética , Mutação , Síndromes de Usher/genética , Alelos , Sequência de Aminoácidos , Proteínas Relacionadas a Caderinas , Análise Mutacional de DNA , Feminino , Ligação Genética , Marcadores Genéticos , Humanos , Masculino , Dados de Sequência Molecular , Fenótipo , Homologia de Sequência de AminoácidosRESUMO
A genome wide linkage analysis of nonsyndromic deafness segregating in a consanguineous Pakistani family (PKDF537) was used to identify DFNB63, a new locus for congenital profound sensorineural hearing loss. A maximum two-point lod score of 6.98 at theta = 0 was obtained for marker D11S1337 (68.55 cM). Genotyping of 550 families revealed three additional families (PKDF295, PKDF702 and PKDF817) segregating hearing loss linked to chromosome 11q13.2-q13.3. Meiotic recombination events in these four families define a critical interval of 4.81 cM bounded by markers D11S4113 (68.01 cM) and D11S4162 (72.82 cM), and SHANK2, FGF-3, TPCN2 and CTTN are among the candidate genes in this interval. Positional identification of this deafness gene should reveal a protein necessary for normal development and/or function of the auditory system.