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1.
Hum Mutat ; 2019 Aug 30.
Artigo em Inglês | MEDLINE | ID: mdl-31469207

RESUMO

Primary ciliary dyskinesia (PCD) is a genetically heterogeneous disease of motile cilia. Even though PCD is widely studied, North-African patients have been rarely explored. In this study, we aim at confirming the clinical diagnosis and explore the genetic spectrum of PCD in a cohort of Tunisian patients. Forty clinically-diagnosed PCD patients belonging to 34 families were recruited from Tunisian pediatric departments. In each proband, targeted capture PCD panel sequencing of the 40 PCD genes was performed. PCD panel sequencing identified bi-allelic mutations in 82% of the families in eight PCD genes. Remarkably, 23.5% of patients carried the same c.2190del CCDC39 mutation. SNP profiling in six unrelated patients carrying this mutation has revealed a founder effect in North-African patients. This mutation is estimated to date back at least 1400-1750 years ago. The identification of this major allele allowed us to suggest a cost-effective genetic diagnostic strategy in North-African PCD patients. This article is protected by copyright. All rights reserved.

2.
Am J Hum Genet ; 105(1): 198-212, 2019 Jul 03.
Artigo em Inglês | MEDLINE | ID: mdl-31178125

RESUMO

Motile cilia and sperm flagella share an evolutionarily conserved axonemal structure. Their structural and/or functional defects are associated with primary ciliary dyskinesia (PCD), a genetic disease characterized by chronic respiratory-tract infections and in which most males are infertile due to asthenozoospermia. Among the well-characterized axonemal protein complexes, the outer dynein arms (ODAs), through ATPase activity of their heavy chains (HCs), play a major role for cilia and flagella beating. However, the contribution of the different HCs (γ-type: DNAH5 and DNAH8 and ß-type: DNAH9, DNAH11, and DNAH17) in ODAs from both organelles is unknown. By analyzing five male individuals who consulted for isolated infertility and displayed a loss of ODAs in their sperm cells but not in their respiratory cells, we identified bi-allelic mutations in DNAH17. The isolated infertility phenotype prompted us to compare the protein composition of ODAs in the sperm and ciliary axonemes from control individuals. We show that DNAH17 and DNAH8, but not DNAH5, DNAH9, or DNAH11, colocalize with α-tubulin along the sperm axoneme, whereas the reverse picture is observed in respiratory cilia, thus explaining the phenotype restricted to sperm cells. We also demonstrate the loss of function associated with DNAH17 mutations in two unrelated individuals by performing immunoblot and immunofluorescence analyses on sperm cells; these analyses indicated the absence of DNAH17 and DNAH8, whereas DNAH2 and DNALI, two inner dynein arm components, were present. Overall, this study demonstrates that mutations in DNAH17 are responsible for isolated male infertility and provides information regarding ODA composition in human spermatozoa.

3.
Hum Mutat ; 2019 Jun 24.
Artigo em Inglês | MEDLINE | ID: mdl-31231873

RESUMO

Isolated growth hormone deficiency (IGHD) is a rare condition mainly caused by mutations in GH1. The aim of this study was to assess the contribution of GHRHR mutations to IGHD in an unusually large group of patients. All GHRHR coding exons and flanking intronic regions were sequenced in 312 unrelated patients with nonsyndromic IGHD. Functional consequences of all newly identified missense variants were assessed in vitro (i.e., study of the expression of recombinant GHRHRs and their ability to activate the cyclic adenosine monophosphate (cAMP) signaling pathway). Genotype-phenotype correlation analyses were performed according to the nature of the identified mutation. We identified 20 different disease-causing GHRHR mutations (truncating and missense loss-of-function mutations), among which 15 are novel, in 24 unrelated patients. Of note, about half (13/24) of those patients represent sporadic cases. The clinical phenotype of patients with at least one missense GHRHR mutation was found to be indistinguishable from that of patients with bi-allelic truncating mutations. This study, which unveils disease-causing GHRHR mutations in 8% (24/312) of IGHD cases, identifies GHRHR as the second IGHD gene most frequently involved after GH1. The finding that 8% of IGHD cases without GH1 mutations are explained by GHRHR molecular defects (including missense mutations), together with the high proportion of sporadic cases among those patients, has important implications for genetic counseling.

5.
Chest ; 155(4): e91-e96, 2019 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-30955586

RESUMO

A nonsmoker man in his 40s underwent bilateral lung transplantation with a referral diagnosis of genetic-related idiopathic pulmonary fibrosis (IPF). The patient had no medical history in childhood and early adulthood, nor was there a family history of IPF. His nonsmoker father presented with lung cancer at 59 years of age. The patient was a professional brass instrument player; he had started playing at 9 years of age, and he was recently playing 3 to 4 h per day. He had a 7-year clinical history of chronic cough and shortness of breath. Bilateral fine crackles were present at clinical examination. There was no digital clubbing. Data had been collected since 2015: no clinical or immunologic signs of connective tissue disease were evident, including autoantibodies for myositis or anti-synthetase syndrome. Chest radiograph showed diffuse interstitial lung disease. Results of pulmonary function tests yielded a restrictive pattern with decreased FVC and decreased total lung capacity (69% and 47% of predicted, respectively). The FEV1/FVC ratio was 86%, and carbon monoxide transfer coefficient was 36% of predicted. BAL cellular analysis consisted of macrophages (66%), lymphocytes (19%; CD4+/CD8+ ratio, 0.16), neutrophils (10%), and eosinophils (5%).

6.
Am J Hum Genet ; 104(2): 229-245, 2019 Feb 07.
Artigo em Inglês | MEDLINE | ID: mdl-30665704

RESUMO

Primary ciliary dyskinesia (PCD) is a genetic disorder in which impaired ciliary function leads to chronic airway disease. Exome sequencing of a PCD subject identified an apparent homozygous frameshift variant, c.887_890delTAAG (p.Val296Glyfs∗13), in exon 5; this frameshift introduces a stop codon in amino acid 308 of the growth arrest-specific protein 2-like 2 (GAS2L2). Further genetic screening of unrelated PCD subjects identified a second proband with a compound heterozygous variant carrying the identical frameshift variant and a large deletion (c.867_∗343+1207del; p.?) starting in exon 5. Both individuals had clinical features of PCD but normal ciliary axoneme structure. In this research, using human nasal cells, mouse models, and X.laevis embryos, we show that GAS2L2 is abundant at the apical surface of ciliated cells, where it localizes with basal bodies, basal feet, rootlets, and actin filaments. Cultured GAS2L2-deficient nasal epithelial cells from one of the affected individuals showed defects in ciliary orientation and had an asynchronous and hyperkinetic (GAS2L2-deficient = 19.8 Hz versus control = 15.8 Hz) ciliary-beat pattern. These results were recapitulated in Gas2l2-/- mouse tracheal epithelial cell (mTEC) cultures and in X. laevis embryos treated with Gas2l2 morpholinos. In mice, the absence of Gas2l2 caused neonatal death, and the conditional deletion of Gas2l2 impaired mucociliary clearance (MCC) and led to mucus accumulation. These results show that a pathogenic variant in GAS2L2 causes a genetic defect in ciliary orientation and impairs MCC and results in PCD.

7.
Am J Hum Genet ; 2018 Nov 20.
Artigo em Inglês | MEDLINE | ID: mdl-30471717

RESUMO

Motile cilia move body fluids and gametes and the beating of cilia lining the airway epithelial surfaces ensures that they are kept clear and protected from inhaled pathogens and consequent respiratory infections. Dynein motor proteins provide mechanical force for cilia beating. Dynein mutations are a common cause of primary ciliary dyskinesia (PCD), an inherited condition characterized by deficient mucociliary clearance and chronic respiratory disease coupled with laterality disturbances and subfertility. Using next-generation sequencing, we detected mutations in the ciliary outer dynein arm (ODA) heavy chain gene DNAH9 in individuals from PCD clinics with situs inversus and in one case male infertility. DNAH9 and its partner heavy chain DNAH5 localize to type 2 ODAs of the distal cilium and in DNAH9-mutated nasal respiratory epithelial cilia we found a loss of DNAH9/DNAH5-containing type 2 ODAs that was restricted to the distal cilia region. This confers a reduced beating frequency with a subtle beating pattern defect affecting the motility of the distal cilia portion. 3D electron tomography ultrastructural studies confirmed regional loss of ODAs from the distal cilium, manifesting as either loss of whole ODA or partial loss of ODA volume. Paramecium DNAH9 knockdown confirms an evolutionarily conserved function for DNAH9 in cilia motility and ODA stability. We find that DNAH9 is widely expressed in the airways, despite DNAH9 mutations appearing to confer symptoms restricted to the upper respiratory tract. In summary, DNAH9 mutations reduce cilia function but some respiratory mucociliary clearance potential may be retained, widening the PCD disease spectrum.

9.
Hum Mol Genet ; 27(2): 266-282, 2018 01 15.
Artigo em Inglês | MEDLINE | ID: mdl-29121203

RESUMO

A child presenting with Mainzer-Saldino syndrome (MZSDS), characterized by renal, retinal and skeletal involvements, was also diagnosed with lung infections and airway ciliary dyskinesia. These manifestations suggested dysfunction of both primary and motile cilia, respectively. Targeted exome sequencing identified biallelic mutations in WDR19, encoding an IFT-A subunit previously associated with MZSDS-related chondrodysplasia, Jeune asphyxiating thoracic dysplasia and cranioectodermal dysplasia, linked to primary cilia dysfunction, and in TEKT1 which encodes tektin-1 an uncharacterized member of the tektin family, mutations of which may cause ciliary dyskinesia. Tektin-1 localizes at the centrosome in cycling cells, at basal bodies of both primary and motile cilia and to the axoneme of motile cilia in airway cells. The identified mutations impaired these localizations. In addition, airway cells from the affected individual showed severe motility defects without major ultrastructural changes. Knockdown of tekt1 in zebrafish resulted in phenotypes consistent with a function for tektin-1 in ciliary motility, which was confirmed by live imaging. Finally, experiments in the zebrafish also revealed a synergistic effect of tekt1 and wdr19. Altogether, our data show genetic interactions between WDR19 and TEKT1 likely contributing to the overall clinical phenotype observed in the affected individual and provide strong evidence for TEKT1 as a new candidate gene for primary ciliary dyskinesia.

11.
Nat Commun ; 8: 14279, 2017 02 08.
Artigo em Inglês | MEDLINE | ID: mdl-28176794

RESUMO

By moving essential body fluids and molecules, motile cilia and flagella govern respiratory mucociliary clearance, laterality determination and the transport of gametes and cerebrospinal fluid. Primary ciliary dyskinesia (PCD) is an autosomal recessive disorder frequently caused by non-assembly of dynein arm motors into cilia and flagella axonemes. Before their import into cilia and flagella, multi-subunit axonemal dynein arms are thought to be stabilized and pre-assembled in the cytoplasm through a DNAAF2-DNAAF4-HSP90 complex akin to the HSP90 co-chaperone R2TP complex. Here, we demonstrate that large genomic deletions as well as point mutations involving PIH1D3 are responsible for an X-linked form of PCD causing disruption of early axonemal dynein assembly. We propose that PIH1D3, a protein that emerges as a new player of the cytoplasmic pre-assembly pathway, is part of a complementary conserved R2TP-like HSP90 co-chaperone complex, the loss of which affects assembly of a subset of inner arm dyneins.


Assuntos
Proteínas Reguladoras de Apoptose/genética , Dineínas do Axonema/metabolismo , Genes Ligados ao Cromossomo X/genética , Doenças Genéticas Ligadas ao Cromossomo X/genética , Síndrome de Kartagener/genética , Adolescente , Adulto , Animais , Proteínas Reguladoras de Apoptose/metabolismo , Axonema/patologia , Criança , Pré-Escolar , Cílios/patologia , Cílios/ultraestrutura , Citoplasma/patologia , Modelos Animais de Doenças , Feminino , Doenças Genéticas Ligadas ao Cromossomo X/patologia , Células HEK293 , Proteínas de Choque Térmico HSP90/metabolismo , Humanos , Recém-Nascido , Síndrome de Kartagener/patologia , Masculino , Microscopia Eletrônica de Transmissão , Linhagem , Filogenia , Mutação Puntual , Dobramento de Proteína , Alinhamento de Sequência , Deleção de Sequência , Motilidade Espermática/genética , Sequenciamento Completo do Exoma , Peixe-Zebra
12.
J Clin Endocrinol Metab ; 102(1): 290-301, 2017 01 01.
Artigo em Inglês | MEDLINE | ID: mdl-27820671

RESUMO

Context: LHX4 encodes a LIM-homeodomain transcription factor that is implicated in early pituitary development. In humans, only 13 heterozygous LHX4 mutations have been associated with congenital hypopituitarism. Objective: The aims of this study were to evaluate the prevalence of LHX4 mutations in patients with hypopituitarism, to define the associated phenotypes, and to characterize the functional impact of the identified variants and the respective role of the 2 LIM domains of LHX4. Design and Patients: We screened 417 unrelated patients with isolated growth hormone deficiency or combined pituitary hormone deficiency associated with ectopic posterior pituitary and/or sella turcica anomalies for LHX4 mutations (Sanger sequencing). In vitro studies were performed to assess the functional consequences of the identified variants. Results: We identified 7 heterozygous variations, including p.(Tyr131*), p.(Arg48Thrfs*104), c.606+1G>T, p.Arg65Val, p.Thr163Pro, p.Arg221Gln, and p.Arg235Gln), that were associated with variable expressivity; 5 of the 7 were also associated with incomplete penetrance. The p.(Tyr131*), p.(Arg48Thrfs*104), p.Ala65Val, p.Thr163Pro, and p.Arg221Gln LHX4 variants are unable to transactivate the POU1F1 and GH promoters. As suggested by transactivation, subcellular localization, and protein-protein interaction studies, p.Arg235Gln is probably a rare polymorphism. Coimmunoprecipitation studies identified LHX3 as a potential protein partner of LHX4. As revealed by functional studies of LIM-defective recombinant LHX4 proteins, the LIM1 and LIM2 domains are not redundant. Conclusion: This study, performed in the largest cohort of patients screened so far for LHX4 mutations, describes 6 disease-causing mutations that are responsible for congenital hypopituitarism. LHX4 mutations were found to be associated with variable expressivity, and most of them with incomplete penetrance; their contribution to pituitary deficits that are associated with an ectopic posterior pituitary and/or a sella turcica defect is ∼1.4% in the 417 probands tested.


Assuntos
Hipopituitarismo/genética , Proteínas com Homeodomínio LIM/genética , Mutação/genética , Fatores de Transcrição/genética , Adolescente , Sequência de Aminoácidos , Biomarcadores/metabolismo , Western Blotting , Criança , Pré-Escolar , Estudos de Coortes , Feminino , Seguimentos , Humanos , Imunoprecipitação , Lactente , Recém-Nascido , Masculino , Linhagem , Prognóstico , Homologia de Sequência de Aminoácidos
13.
Eur Respir J ; 49(1)2017 01.
Artigo em Inglês | MEDLINE | ID: mdl-27836958

RESUMO

The diagnosis of primary ciliary dyskinesia is often confirmed with standard, albeit complex and expensive, tests. In many cases, however, the diagnosis remains difficult despite the array of sophisticated diagnostic tests. There is no "gold standard" reference test. Hence, a Task Force supported by the European Respiratory Society has developed this guideline to provide evidence-based recommendations on diagnostic testing, especially in light of new developments in such tests, and the need for robust diagnoses of patients who might enter randomised controlled trials of treatments. The guideline is based on pre-defined questions relevant for clinical care, a systematic review of the literature, and assessment of the evidence using the GRADE (Grading of Recommendations, Assessment, Development and Evaluation) approach. It focuses on clinical presentation, nasal nitric oxide, analysis of ciliary beat frequency and pattern by high-speed video-microscopy analysis, transmission electron microscopy, genotyping and immunofluorescence. It then used a modified Delphi survey to develop an algorithm for the use of diagnostic tests to definitively confirm and exclude the diagnosis of primary ciliary dyskinesia; and to provide advice when the diagnosis was not conclusive. Finally, this guideline proposes a set of quality criteria for future research on the validity of diagnostic methods for primary ciliary dyskinesia.


Assuntos
Cílios/ultraestrutura , Síndrome de Kartagener/diagnóstico , Cílios/patologia , Técnica Delfos , Diagnóstico Diferencial , Europa (Continente) , Imunofluorescência , Testes Genéticos , Humanos , Síndrome de Kartagener/genética , Microscopia Eletrônica de Transmissão , Microscopia de Vídeo , Óxido Nítrico/análise , Literatura de Revisão como Assunto , Sociedades Médicas
14.
Joint Bone Spine ; 84(2): 159-162, 2017 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-27238193

RESUMO

OBJECTIVES: Familial mediterranean fever (FMF) is the most common monogenic autoinflammatory disease. Hidradenitis suppurativa (HS) is an inflammatory cutaneous disease. Those diseases can occur simultaneously among the same individual. Our objective was to describe the features of patients displaying both FMF and HS. METHODS: We screened the French adult FMF reference center for FMF patients with HS. RESULTS: Six patients out of 151 (4%) with a median age of 36 years old were concerned. Among them, FMF was symptomatic at a median age of 11.5years old and colchicine was introduced at a median age of 20.5years old. HS was diagnosed at a median age of 31.5years old. An elderly patient displayed AA amyloidosis in the outcome of FMF, with a late diagnosis of HS, with response to anakinra. There was no temporal relation between FMF and HS attacks. Some patients had a persistent inflammatory syndrome under treatment. CONCLUSION: FMF and HS are both inflammatory diseases involving young patients, with HS possibly being an autoinflammatory disease. Although their association seems to be fortuitous, both can induce an important inflammation state that could lead to AA amyloidosis and require a close monitoring of clinical signs and acute-phase reactants. Anakinra was successful in treating the only patient with both HS, FMF and amyloidosis.


Assuntos
Febre Familiar do Mediterrâneo/complicações , Hidradenite Supurativa/complicações , Adulto , Idoso , Febre Familiar do Mediterrâneo/diagnóstico , Feminino , Hidradenite Supurativa/diagnóstico , Humanos , Masculino , Pessoa de Meia-Idade
15.
Sex Dev ; 11(5-6): 293-297, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-29332064

RESUMO

A heterozygous intragenic duplication within the repeated area (CTGCAGCTG)×2 of the NR5A1 gene was found in a 15-year-old 46,XY DSD (disorders/differences of sex development) patient with micropenis and severe proximal hypospadias. This heterozygous duplication has already been described twice in boys with a similar phenotype, whereas a deletion of 3 amino acids at the same position in the protein SF-1 has been described in a 46,XX patient with primary ovarian failure and short stature. These data suggest that this region within the NR5A1 gene has an important role for SF-1 protein function in gonads and is a hotspot for intragenic rearrangements.


Assuntos
Transtorno 46,XY do Desenvolvimento Sexual/genética , Hipospadia/genética , Fator Esteroidogênico 1/genética , Adolescente , Heterozigoto , Humanos , Hipospadia/metabolismo , Masculino , Mutação/genética , Fator Esteroidogênico 1/metabolismo
16.
Am J Hum Genet ; 99(2): 489-500, 2016 08 04.
Artigo em Inglês | MEDLINE | ID: mdl-27486783

RESUMO

Primary ciliary dyskinesia (PCD) is an autosomal-recessive disease due to functional or ultra-structural defects of motile cilia. Affected individuals display recurrent respiratory-tract infections; most males are infertile as a result of sperm flagellar dysfunction. The great majority of the PCD-associated genes identified so far encode either components of dynein arms (DAs), which are multiprotein-ATPase complexes essential for ciliary motility, or proteins involved in DA assembly. To identify the molecular basis of a PCD phenotype characterized by central complex (CC) defects but normal DA structure, a phenotype found in ∼15% of cases, we performed whole-exome sequencing in a male individual with PCD and unexplained CC defects. This analysis, combined with whole-genome SNP genotyping, identified a homozygous mutation in DNAJB13 (c.833T>G), a gene encoding a HSP40 co-chaperone whose ortholog in the flagellated alga Chlamydomonas localizes to the radial spokes. In vitro studies showed that this missense substitution (p.Met278Arg), which involves a highly conserved residue of several HSP40 family members, leads to protein instability and triggers proteasomal degradation, a result confirmed by the absence of endogenous DNAJB13 in cilia and sperm from this individual. Subsequent DNAJB13 analyses identified another homozygous mutation in a second family; the study of DNAJB13 transcripts obtained from airway cells showed that this mutation (c.68+1G>C) results in a splicing defect consistent with a loss-of-function mutation. Overall, this study, which establishes mutations in DNAJB13 as a cause of PCD, unveils the key role played by DNAJB13 in the proper formation and function of ciliary and flagellar axonemes in humans.


Assuntos
Transtornos da Motilidade Ciliar/genética , Proteínas de Choque Térmico/genética , Infertilidade Masculina/genética , Mutação , Adolescente , Axonema/genética , Cílios/genética , Transtornos da Motilidade Ciliar/patologia , Exoma/genética , Feminino , Flagelos/genética , Flagelos/patologia , Proteínas de Choque Térmico HSP40/metabolismo , Proteínas de Choque Térmico/metabolismo , Homozigoto , Humanos , Infertilidade Masculina/patologia , Síndrome de Kartagener/genética , Masculino , Pessoa de Meia-Idade , Mutação de Sentido Incorreto/genética , Fenótipo , Polimorfismo de Nucleotídeo Único/genética , Complexo de Endopeptidases do Proteassoma/metabolismo , Estabilidade Proteica , Processamento de RNA/genética , Sêmen , Espermatozoides/metabolismo , Espermatozoides/patologia
17.
Hum Mutat ; 37(8): 776-85, 2016 08.
Artigo em Inglês | MEDLINE | ID: mdl-27120127

RESUMO

Primary ciliary dyskinesia (PCD) is an autosomal recessive disease characterized by chronic respiratory infections of the upper and lower airways, hypofertility, and, in approximately half of the cases, situs inversus. This complex phenotype results from defects in motile cilia and sperm flagella. Among the numerous genes involved in PCD, very few-including CCDC39 and CCDC40-carry mutations that lead to a disorganization of ciliary axonemes with microtubule misalignment. Focusing on this particular phenotype, we identified bi-allelic loss-of-function mutations in GAS8, a gene that encodes a subunit of the nexin-dynein regulatory complex (N-DRC) orthologous to DRC4 of the flagellated alga Chlamydomonas reinhardtii. Unlike the majority of PCD patients, individuals with GAS8 mutations have motile cilia, which, as documented by high-speed videomicroscopy, display a subtle beating pattern defect characterized by slightly reduced bending amplitude. Immunofluorescence studies performed on patients' respiratory cilia revealed that GAS8 is not required for the proper expression of CCDC39 and CCDC40. Rather, mutations in GAS8 affect the subcellular localization of another N-DRC subunit called DRC3. Overall, this study, which identifies GAS8 as a PCD gene, unveils the key importance of the corresponding protein in N-DRC integrity and in the proper alignment of axonemal microtubules in humans.


Assuntos
Axonema/patologia , Proteínas do Citoesqueleto/genética , Síndrome de Kartagener/genética , Mutação , Proteínas de Neoplasias/genética , Adulto , Criança , Proteínas do Citoesqueleto/metabolismo , Feminino , Predisposição Genética para Doença , Sequenciamento de Nucleotídeos em Larga Escala , Humanos , Síndrome de Kartagener/metabolismo , Síndrome de Kartagener/patologia , Masculino , Proteínas de Neoplasias/metabolismo , Análise de Sequência de DNA
18.
Hum Mol Genet ; 25(8): 1457-67, 2016 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-26792177

RESUMO

Idiopathic interstitial pneumonias (IIPs) comprise a heterogeneous group of rare lung parenchyma disorders with high morbidity and mortality, which can occur at all ages. In adults, the most common form of IIPs, idiopathic pulmonary fibrosis (IPF), has been associated with an increased frequency of lung cancer. The molecular basis of IIPs remains unknown in most cases. This study investigates IIP pathophysiology in 12 families affected by IPF and lung cancer. We identified, in a multigenerational family, nine members carrying a heterozygous missense mutation with evidence of pathogenicity in SFTPA1 that encodes the surfactant protein (SP)-A1. The mutation (p.Trp211Arg), which segregates with a disease phenotype characterized by either isolated IIP/IPF, or IPF associated with lung adenocarcinoma, is located in the carbohydrate recognition domain (CRD) of SP-A1 and involves a residue invariant throughout evolution, not only in SP-A1, but also in its close paralog SP-A2 and other CRD-containing proteins. As shown through functional studies, the p.Trp211Arg mutation impairs SP-A1 secretion. Immunohistochemistry studies on patient alveolar epithelium showed an altered SP-A expression pattern. Overall, this first report of a germline molecular defect in SFTPA1 unveils the key role of SP-A1 in the occurrence of several chronic respiratory diseases, ranging from severe respiratory insufficiency occurring early in life to the association of lung fibrosis and cancer in adult patients. These data also clearly show that, in spite of their structural and functional similarities, SP-A1 and SP-A2 are not redundant.


Assuntos
Mutação em Linhagem Germinativa , Pneumonias Intersticiais Idiopáticas/genética , Neoplasias Pulmonares/genética , Mutação de Sentido Incorreto , Proteína A Associada a Surfactante Pulmonar/genética , Adulto , Idoso , Feminino , Regulação da Expressão Gênica , Predisposição Genética para Doença , Humanos , Pneumonias Intersticiais Idiopáticas/patologia , Neoplasias Pulmonares/patologia , Masculino , Pessoa de Meia-Idade , Linhagem , Proteína A Associada a Surfactante Pulmonar/metabolismo , Análise de Sequência de DNA
20.
Am J Hum Genet ; 97(1): 153-62, 2015 Jul 02.
Artigo em Inglês | MEDLINE | ID: mdl-26073779

RESUMO

Primary ciliary dyskinesia (PCD) is a rare autosomal-recessive condition resulting from structural and/or functional defects of the axoneme in motile cilia and sperm flagella. The great majority of mutations identified so far involve genes whose defects result in dynein-arm anomalies. By contrast, PCD due to CC/RS defects (those in the central complex [CC] and radial spokes [RSs]), which might be difficult to diagnose, remains mostly unexplained. We identified non-ambiguous RSPH3 mutations in 5 of 48 independent families affected by CC/RS defects. RSPH3, whose ortholog in the flagellated alga Chlamydomonas reinhardtii encodes a RS-stalk protein, is mainly expressed in respiratory and testicular cells. Its protein product, which localizes within the cilia of respiratory epithelial cells, was undetectable in airway cells from an individual with RSPH3 mutations and in whom RSPH23 (a RS-neck protein) and RSPH1 and RSPH4A (RS-head proteins) were found to be still present within cilia. In the case of RSPH3 mutations, high-speed-videomicroscopy analyses revealed the coexistence of immotile cilia and motile cilia with movements of reduced amplitude. A striking feature of the ultrastructural phenotype associated with RSPH3 mutations is the near absence of detectable RSs in all cilia in combination with a variable proportion of cilia with CC defects. Overall, this study shows that RSPH3 mutations contribute to disease in more than 10% of PCD-affected individuals with CC/RS defects, thereby allowing an accurate diagnosis to be made in such cases. It also unveils the key role of RSPH3 in the proper building of RSs and the CC in humans.


Assuntos
Cílios/genética , Síndrome de Kartagener/genética , Síndrome de Kartagener/patologia , Mutação/genética , Proteínas do Tecido Nervoso/genética , Fenótipo , Cílios/ultraestrutura , Predisposição Genética para Doença , Humanos , Microscopia de Vídeo
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