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Heike Olbrich - One of the best experts on this subject based on the ideXlab platform.
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Genetic profile, nasal Nitric Oxide and age at diagnosis in 60 Danish PCD patients
Paediatric respiratory infection and immun., 2019Co-Authors: June K. Marthin, Niki T Loges, Heike Olbrich, Heymut Omran, Maria C. Philipsen, Morten Duno, Petra Pennekamp, Christine Edelbusch, Kim G. NielsenAbstract:In Primary Ciliary Dyskinesia (PCD) genotype-phenotype characterization is warranted to further understand the heterogeneity of the disease Aim: To describe the distribution of pathogenic variants in the Danish PCD cohort and relate nasal Nitric Oxide (nNO) and age at diagnosis to the specific genetic aberration Methods: Genetic testing was performed in two labs, Copenhagen, DK and Omran Lab Munster, Germany, respectively. In Copenhagen we performed targeted NGS analysis of 33 genes associated with PCD, in Munster 38 candidate genes were analyzed nNO data were included. Age at diagnosis was defined as the date of initial PCD testing Results: 60 patients with classic PCD phenotype, verified biallelic mutations and a nNO test were included. Distribution of patients according to PCD gene defect is shown in Figure 1: Half the patients with CCDC39/40 were diagnosed at age above 5 years, hence not early. Four PCD patients showed nNO in normal range, not associated to specific mutations, Table 1: Conclusions: In this Danish cohort CCDC40 outnumbered DNAH5 Neither age at diagnosis nor nNO in normal range were associated with specific PCD genes. Normal nNO included patients with biallelic CCDC40 and DNAH5 mutations stressing that nNO cannot stand alone in excluding PCD
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MCIDAS mutations result in a mucociliary clearance disorder with reduced generation of multiple motile cilia
Nature communications, 2014Co-Authors: Mieke Boon, Niki T Loges, Heike Olbrich, Gerard W. Dougherty, Julia Wallmeier, Martine Jaspers, Johanna Raidt, Claudius Werner, Israel AmiravAbstract:Reduced generation of multiple motile cilia (RGMC) is a rare mucociliary clearance disorder. Affected persons suffer from recurrent infections of upper and lower airways because of highly reduced numbers of multiple motile respiratory cilia. Here we report recessive loss-of-function and missense mutations in MCIDAS-encoding Multicilin, which was shown to promote the early steps of multiciliated cell differentiation in Xenopus. MCIDAS mutant respiratory epithelial cells carry only one or two cilia per cell, which lack ciliary motility-related proteins (DNAH5; CCDC39) as seen in primary ciliary dyskinesia. Consistent with this finding, FOXJ1-regulating axonemal motor protein expression is absent in respiratory cells of MCIDAS mutant individuals. CCNO, when mutated known to cause RGMC, is also absent in MCIDAS mutant respiratory cells, consistent with its downstream activity. Thus, our findings identify Multicilin as a key regulator of CCNO/FOXJ1 for human multiciliated cell differentiation, and highlight the 5q11 region containing CCNO and MCIDAS as a locus underlying RGMC.
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Targeted testing for DNAI1 hot spot-mutation utilizing immunofluorescence microscopy findings
Cilia, 2012Co-Authors: M Szczepaniak, Niki T Loges, Heike Olbrich, Michał Witt, Heymut OmranAbstract:Primary ciliary dyskinesia (PCD) is a rare (prevalence 1/20,000) genetic disease affecting motile cilia in the respiratory epithelium, spermatozoid flagella and primary cilia in the embryonic node. The most frequent (~60-70%) structural defect identified by TEM in the cilia of PCD patients are abnormal dynein arms. Several genes can cause PCD, but the majority of mutations were found in DNAH5 and DNAI1 genes (respectively ~28% and 4-10% of all cases), which encode heavy and intermediate chains of the outer dynein arms (ODAs), respectively. Mutations in both genes account collectively for almost 40% of PCD cases [Olbrich et al. 2002, Hornef et al. 2006, Zariwala et al. 2006, Zietkiewicz et al. 2010]. The hot-spot mutation in the DNAI1 gene appears in intron 1, with the frequency of the most popular mutation (IVS1+2_3insT, causes aberrant splicing) around 55% of all DNAI1 mutations. We have previously shown in a few PCD cases that proximal type-1 ODA complexes can be at least partially assembled in DNAI1– mutant cilia [Fliegauf et al. 2005]. We analysed the frequency of this hot spot mutation among 51 patients, in which immunofluorescence has identified abnormal ODA staining (proximal presence of DNAH5). The prevalence of the mutation in intron 1 of DNAI1 gene will be confirmed by PCR and restriction enzyme digestion. In addition, we analyzed respiratory cilia for the inner dynein arm component DNALI1 localization, which we expect not to be altered in DNAI1 mutant cilia, contrasting the findings present in KTU- mutant cilia.
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deletions and point mutations of lrrc50 cause primary ciliary dyskinesia due to dynein arm defects
American Journal of Human Genetics, 2009Co-Authors: Niki T Loges, Maimoona A Zariwala, Heike Olbrich, Karsten Haffner, Andreas Kispert, Anita Beckerheck, Angelina Heer, Christina Reinhard, Miriam Schmidts, Margaret W LeighAbstract:Genetic defects affecting motility of cilia and flagella cause chronic destructive airway disease, randomization of left-right body asymmetry, and, frequently, male infertility in primary ciliary dyskinesia (PCD). The most frequent defects involve outer and inner dynein arms (ODAs and IDAs) that are large multiprotein complexes responsible for cilia-beat generation and regulation, respectively. Here, we demonstrate that large genomic deletions, as well as point mutations involving LRRC50, are responsible for a distinct PCD variant that is characterized by a combined defect involving assembly of the ODAs and IDAs. Functional analyses showed that LRRC50 deficiency disrupts assembly of distally and proximally DNAH5- and DNAI2-containing ODA complexes, as well as DNALI1-containing IDA complexes, resulting in immotile cilia. On the basis of these findings, we assume that LRRC50 plays a role in assembly of distinct dynein-arm complexes.
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mutations of dnai1 in primary ciliary dyskinesia evidence of founder effect in a common mutation
American Journal of Respiratory and Critical Care Medicine, 2006Co-Authors: Maimoona B Zariwala, Margaret W Leigh, Judit Horvath, Marcus P Kennedy, Peadar G Noone, Milan J. Hazucha, Franck Ceppa, Johnny L Carson, Adriana Lori, Heike OlbrichAbstract:Rationale: Primary ciliary dyskinesia (PCD) is a rare, usually autosomal recessive, genetic disorder characterized by ciliary dysfunction, sino-pulmonary disease, and situs inversus. Disease-causing mutations have been reported in DNAI1 and DNAH5 encoding outer dynein arm (ODA) proteins of cilia.Objectives: We analyzed DNAI1 to identify disease-causing mutations in PCD and to determine if the previously reported IVS1+2_3insT (219+3insT) mutation represents a “founder” or “hot spot” mutation.Methods: Patients with PCD from 179 unrelated families were studied. Exclusion mapping showed no linkage to DNAI1 for 13 families; the entire coding region was sequenced in a patient from the remaining 166 families. Reverse transcriptase–polymerase chain reaction (RT-PCR) was performed on nasal epithelial RNA in 14 families.Results: Mutations in DNAI1 including 12 novel mutations were identified in 16 of 179 (9%) families; 14 harbored biallelic mutations. Deep intronic splice mutations were not identified by reverse tr...
Heymut Omran - One of the best experts on this subject based on the ideXlab platform.
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Genetic profile, nasal Nitric Oxide and age at diagnosis in 60 Danish PCD patients
Paediatric respiratory infection and immun., 2019Co-Authors: June K. Marthin, Niki T Loges, Heike Olbrich, Heymut Omran, Maria C. Philipsen, Morten Duno, Petra Pennekamp, Christine Edelbusch, Kim G. NielsenAbstract:In Primary Ciliary Dyskinesia (PCD) genotype-phenotype characterization is warranted to further understand the heterogeneity of the disease Aim: To describe the distribution of pathogenic variants in the Danish PCD cohort and relate nasal Nitric Oxide (nNO) and age at diagnosis to the specific genetic aberration Methods: Genetic testing was performed in two labs, Copenhagen, DK and Omran Lab Munster, Germany, respectively. In Copenhagen we performed targeted NGS analysis of 33 genes associated with PCD, in Munster 38 candidate genes were analyzed nNO data were included. Age at diagnosis was defined as the date of initial PCD testing Results: 60 patients with classic PCD phenotype, verified biallelic mutations and a nNO test were included. Distribution of patients according to PCD gene defect is shown in Figure 1: Half the patients with CCDC39/40 were diagnosed at age above 5 years, hence not early. Four PCD patients showed nNO in normal range, not associated to specific mutations, Table 1: Conclusions: In this Danish cohort CCDC40 outnumbered DNAH5 Neither age at diagnosis nor nNO in normal range were associated with specific PCD genes. Normal nNO included patients with biallelic CCDC40 and DNAH5 mutations stressing that nNO cannot stand alone in excluding PCD
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Immunofluorescence microscopy (IFM) analysis of primary ciliary dyskinesia (PCD) patients with suspected inner dynein arm defects (IDA)
Cilia, 2012Co-Authors: Rim Hjeij, Niki T Loges, Anita Becker-heck, Heymut OmranAbstract:Primary ciliary dyskinesia (PCD), characterized by abnormal motility of cilia or flagella, is caused by defects of structural components such as inner dynein arms (IDAs). Recently high-speed videomicroscopy has substituted transmission electron microscopy (TEM) analysis as the “gold standard” for diagnosis. However, TEM is still the most widely used diagnostic tool in many countries. A recent study reported that isolated IDA defects is the most frequent (> 50%) ciliary defect in PCD, as detected by TEM (Theegarten, 2011). IFM analysis has shown in several studies that it can ascertain diagnosis such as in PCD variants caused by DNAH5, DNAI1, DNAI2, KTU, LRRC50, CCDC39 and CCDC40 mutations. IFM can provide a complete view of the ciliary axoneme and identify “partial” axonemal defects which may be misinterpreted by TEM (e.g. present in KTU mutant cilia). Here we performed IFM analysis of known PCD patients to identify the composition of dynein arm defects, including IDAs. Using antibodies specific to the IDA marker DNALI1, we determined that the frequency of isolated IDA defects is unexpected low (thus far, only 12 of ~800 PCD patients, ~1.5%). In contrast, we observe that IDA defects usually accompany DRC defects (absent/abnormal Gas11) or ODA defects (absent/abnormal DNAH5). Because the DNALI1 antibody is targeted against only 3 IDA isoforms out of 7, we are currently screening additional IDA-specific antibodies for IFM analysis to target the other IDA sub-types which escaped our analysis. However, our results suggest the percentage of isolated IDA defects might be lower than previously expected.
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Targeted testing for DNAI1 hot spot-mutation utilizing immunofluorescence microscopy findings
Cilia, 2012Co-Authors: M Szczepaniak, Niki T Loges, Heike Olbrich, Michał Witt, Heymut OmranAbstract:Primary ciliary dyskinesia (PCD) is a rare (prevalence 1/20,000) genetic disease affecting motile cilia in the respiratory epithelium, spermatozoid flagella and primary cilia in the embryonic node. The most frequent (~60-70%) structural defect identified by TEM in the cilia of PCD patients are abnormal dynein arms. Several genes can cause PCD, but the majority of mutations were found in DNAH5 and DNAI1 genes (respectively ~28% and 4-10% of all cases), which encode heavy and intermediate chains of the outer dynein arms (ODAs), respectively. Mutations in both genes account collectively for almost 40% of PCD cases [Olbrich et al. 2002, Hornef et al. 2006, Zariwala et al. 2006, Zietkiewicz et al. 2010]. The hot-spot mutation in the DNAI1 gene appears in intron 1, with the frequency of the most popular mutation (IVS1+2_3insT, causes aberrant splicing) around 55% of all DNAI1 mutations. We have previously shown in a few PCD cases that proximal type-1 ODA complexes can be at least partially assembled in DNAI1– mutant cilia [Fliegauf et al. 2005]. We analysed the frequency of this hot spot mutation among 51 patients, in which immunofluorescence has identified abnormal ODA staining (proximal presence of DNAH5). The prevalence of the mutation in intron 1 of DNAI1 gene will be confirmed by PCR and restriction enzyme digestion. In addition, we analyzed respiratory cilia for the inner dynein arm component DNALI1 localization, which we expect not to be altered in DNAI1 mutant cilia, contrasting the findings present in KTU- mutant cilia.
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Genetic Defects in Ciliary Structure and Function
Annual review of physiology, 2007Co-Authors: Maimoona A Zariwala, Michael R. Knowles, Heymut OmranAbstract:AbstractCilia, hair-like structures extending from the cell membrane, perform diverse biological functions. Primary (genetic) defects in the structure and function of sensory and motile cilia result in multiple ciliopathies. The most prominent genetic abnormality involving motile cilia (and the respiratory tract) is primary ciliary dyskinesia (PCD). PCD is a rare, usually autosomal recessive, genetically heterogeneous disorder characterized by sino-pulmonary disease, laterality defects, and male infertility. Ciliary ultrastructural defects are identified in ∼90% of PCD patients and involve the outer dynein arms, inner dynein arms, or both. Diagnosing PCD is challenging and requires a compatible clinical phenotype together with tests such as ciliary ultrastructural analysis, immunofluorescent staining, ciliary beat assessment, and/or nasal nitric oxide measurements. Recent mutational analysis demonstrated that 38% of PCD patients carry mutations of the dynein genes DNAI1 and DNAH5. Increased understanding ...
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axonemal localization of the dynein component DNAH5 is not altered in secondary ciliary dyskinesia
Pediatric Research, 2006Co-Authors: Heike Olbrich, Niki T Loges, Judit Horvath, Andrea Fekete, Karin Storm Vans Gravesande, Andreas Blum, Karl Hormann, Heymut OmranAbstract:Primary ciliary dyskinesia (PCD) is a heterogeneous genetic disorder characterized by recurrent airway infections and situs inversus in half of affected individuals. Diagnosis currently relies on demonstration of abnormal ciliary ultrastructure or altered ciliary beat. Alterations encountered in secondary ciliary dyskinesia (SCD) caused by inflammation often complicate the diagnostic workup. We have recently shown that in respiratory epithelial cells from PCD patients with outer dynein arm defects the dynein protein DNAH5 is mislocalized and either completely or partially absent from the ciliary axoneme. In this study, we addressed the question whether SCD might affect axonemal DNAH5 localization in respiratory cells. To induce SCD in vitro, we treated primary human respiratory epithelial cell cultures with interleukin-13 (IL-13). Ciliary function and ultrastructure were assessed by high-speed videomicroscopy and transmission electron microscopy, respectively. For in vivo localization of DNAH5, we performed nasal brushing biopsies in patients with evidence of SCD. Expression of DNAH5 was analyzed by immunofluorescence microscopy. IL-13-treated cells showed evidence of SCD. Ciliary beat frequency was significantly reduced and ultrastructural analyses showed axonemal disorganization compared with control cells. High-resolution immunofluorescence studies of respiratory epithelial cells with SCD identified in vitro and in vivo normal axonemal DNAH5 localization. DNAH5 localization is not altered by SCD, indicating a high potential for immunofluorescence analysis as a novel diagnostic tool in PCD.
Niki T Loges - One of the best experts on this subject based on the ideXlab platform.
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Genetic profile, nasal Nitric Oxide and age at diagnosis in 60 Danish PCD patients
Paediatric respiratory infection and immun., 2019Co-Authors: June K. Marthin, Niki T Loges, Heike Olbrich, Heymut Omran, Maria C. Philipsen, Morten Duno, Petra Pennekamp, Christine Edelbusch, Kim G. NielsenAbstract:In Primary Ciliary Dyskinesia (PCD) genotype-phenotype characterization is warranted to further understand the heterogeneity of the disease Aim: To describe the distribution of pathogenic variants in the Danish PCD cohort and relate nasal Nitric Oxide (nNO) and age at diagnosis to the specific genetic aberration Methods: Genetic testing was performed in two labs, Copenhagen, DK and Omran Lab Munster, Germany, respectively. In Copenhagen we performed targeted NGS analysis of 33 genes associated with PCD, in Munster 38 candidate genes were analyzed nNO data were included. Age at diagnosis was defined as the date of initial PCD testing Results: 60 patients with classic PCD phenotype, verified biallelic mutations and a nNO test were included. Distribution of patients according to PCD gene defect is shown in Figure 1: Half the patients with CCDC39/40 were diagnosed at age above 5 years, hence not early. Four PCD patients showed nNO in normal range, not associated to specific mutations, Table 1: Conclusions: In this Danish cohort CCDC40 outnumbered DNAH5 Neither age at diagnosis nor nNO in normal range were associated with specific PCD genes. Normal nNO included patients with biallelic CCDC40 and DNAH5 mutations stressing that nNO cannot stand alone in excluding PCD
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recessive dnah9 loss of function mutations cause laterality defects and subtle respiratory ciliary beating defects
American Journal of Human Genetics, 2018Co-Authors: Niki T Loges, Dinu Antony, Ales Maver, Matthew A Deardorff, Elif Yýlmaz Gulec, Alper Gezdirici, Tabea Nothemenchen, Inga M Hoben, Lena Jelten, Diana FrankAbstract:Dysfunction of motile monocilia, altering the leftward flow at the embryonic node essential for determination of left-right body asymmetry, is a major cause of laterality defects. Laterality defects are also often associated with reduced mucociliary clearance caused by defective multiple motile cilia of the airway and are responsible for destructive airway disease. Outer dynein arms (ODAs) are essential for ciliary beat generation, and human respiratory cilia contain different ODA heavy chains (HCs): the panaxonemally distributed γ-HC DNAH5, proximally located β-HC DNAH11 (defining ODA type 1), and the distally localized β-HC DNAH9 (defining ODA type 2). Here we report loss-of-function mutations in DNAH9 in five independent families causing situs abnormalities associated with subtle respiratory ciliary dysfunction. Consistent with the observed subtle respiratory phenotype, high-speed video microscopy demonstrates distally impaired ciliary bending in DNAH9 mutant respiratory cilia. DNAH9-deficient cilia also lack other ODA components such as DNAH5, DNAI1, and DNAI2 from the distal axonemal compartment, demonstrating an essential role of DNAH9 for distal axonemal assembly of ODAs type 2. Yeast two-hybrid and co-immunoprecipitation analyses indicate interaction of DNAH9 with the ODA components DNAH5 and DNAI2 as well as the ODA-docking complex component CCDC114. We further show that during ciliogenesis of respiratory cilia, first proximally located DNAH11 and then distally located DNAH9 is assembled in the axoneme. We propose that the β-HC paralogs DNAH9 and DNAH11 achieved specific functional roles for the distinct axonemal compartments during evolution with human DNAH9 function matching that of ancient β-HCs such as that of the unicellular Chlamydomonas reinhardtii.
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MCIDAS mutations result in a mucociliary clearance disorder with reduced generation of multiple motile cilia
Nature communications, 2014Co-Authors: Mieke Boon, Niki T Loges, Heike Olbrich, Gerard W. Dougherty, Julia Wallmeier, Martine Jaspers, Johanna Raidt, Claudius Werner, Israel AmiravAbstract:Reduced generation of multiple motile cilia (RGMC) is a rare mucociliary clearance disorder. Affected persons suffer from recurrent infections of upper and lower airways because of highly reduced numbers of multiple motile respiratory cilia. Here we report recessive loss-of-function and missense mutations in MCIDAS-encoding Multicilin, which was shown to promote the early steps of multiciliated cell differentiation in Xenopus. MCIDAS mutant respiratory epithelial cells carry only one or two cilia per cell, which lack ciliary motility-related proteins (DNAH5; CCDC39) as seen in primary ciliary dyskinesia. Consistent with this finding, FOXJ1-regulating axonemal motor protein expression is absent in respiratory cells of MCIDAS mutant individuals. CCNO, when mutated known to cause RGMC, is also absent in MCIDAS mutant respiratory cells, consistent with its downstream activity. Thus, our findings identify Multicilin as a key regulator of CCNO/FOXJ1 for human multiciliated cell differentiation, and highlight the 5q11 region containing CCNO and MCIDAS as a locus underlying RGMC.
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Immunofluorescence microscopy (IFM) analysis of primary ciliary dyskinesia (PCD) patients with suspected inner dynein arm defects (IDA)
Cilia, 2012Co-Authors: Rim Hjeij, Niki T Loges, Anita Becker-heck, Heymut OmranAbstract:Primary ciliary dyskinesia (PCD), characterized by abnormal motility of cilia or flagella, is caused by defects of structural components such as inner dynein arms (IDAs). Recently high-speed videomicroscopy has substituted transmission electron microscopy (TEM) analysis as the “gold standard” for diagnosis. However, TEM is still the most widely used diagnostic tool in many countries. A recent study reported that isolated IDA defects is the most frequent (> 50%) ciliary defect in PCD, as detected by TEM (Theegarten, 2011). IFM analysis has shown in several studies that it can ascertain diagnosis such as in PCD variants caused by DNAH5, DNAI1, DNAI2, KTU, LRRC50, CCDC39 and CCDC40 mutations. IFM can provide a complete view of the ciliary axoneme and identify “partial” axonemal defects which may be misinterpreted by TEM (e.g. present in KTU mutant cilia). Here we performed IFM analysis of known PCD patients to identify the composition of dynein arm defects, including IDAs. Using antibodies specific to the IDA marker DNALI1, we determined that the frequency of isolated IDA defects is unexpected low (thus far, only 12 of ~800 PCD patients, ~1.5%). In contrast, we observe that IDA defects usually accompany DRC defects (absent/abnormal Gas11) or ODA defects (absent/abnormal DNAH5). Because the DNALI1 antibody is targeted against only 3 IDA isoforms out of 7, we are currently screening additional IDA-specific antibodies for IFM analysis to target the other IDA sub-types which escaped our analysis. However, our results suggest the percentage of isolated IDA defects might be lower than previously expected.
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Targeted testing for DNAI1 hot spot-mutation utilizing immunofluorescence microscopy findings
Cilia, 2012Co-Authors: M Szczepaniak, Niki T Loges, Heike Olbrich, Michał Witt, Heymut OmranAbstract:Primary ciliary dyskinesia (PCD) is a rare (prevalence 1/20,000) genetic disease affecting motile cilia in the respiratory epithelium, spermatozoid flagella and primary cilia in the embryonic node. The most frequent (~60-70%) structural defect identified by TEM in the cilia of PCD patients are abnormal dynein arms. Several genes can cause PCD, but the majority of mutations were found in DNAH5 and DNAI1 genes (respectively ~28% and 4-10% of all cases), which encode heavy and intermediate chains of the outer dynein arms (ODAs), respectively. Mutations in both genes account collectively for almost 40% of PCD cases [Olbrich et al. 2002, Hornef et al. 2006, Zariwala et al. 2006, Zietkiewicz et al. 2010]. The hot-spot mutation in the DNAI1 gene appears in intron 1, with the frequency of the most popular mutation (IVS1+2_3insT, causes aberrant splicing) around 55% of all DNAI1 mutations. We have previously shown in a few PCD cases that proximal type-1 ODA complexes can be at least partially assembled in DNAI1– mutant cilia [Fliegauf et al. 2005]. We analysed the frequency of this hot spot mutation among 51 patients, in which immunofluorescence has identified abnormal ODA staining (proximal presence of DNAH5). The prevalence of the mutation in intron 1 of DNAI1 gene will be confirmed by PCR and restriction enzyme digestion. In addition, we analyzed respiratory cilia for the inner dynein arm component DNALI1 localization, which we expect not to be altered in DNAI1 mutant cilia, contrasting the findings present in KTU- mutant cilia.
Maimoona A Zariwala - One of the best experts on this subject based on the ideXlab platform.
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Carrier frequencies of eleven mutations in eight genes associated with primary ciliary dyskinesia in the Ashkenazi Jewish population.
Molecular genetics & genomic medicine, 2014Co-Authors: Anastasia Fedick, Michael R. Knowles, Chaim Jalas, Nathan R. Treff, Maimoona A ZariwalaAbstract:Primary ciliary dyskinesia (PCD) is a genetically heterogeneous, autosomal recessive disorder that results from functional and ultrastructural abnormalities of motile cilia. Patients with PCD have diverse clinical phenotypes that include chronic upper and lower respiratory tract infections, situs inversus, heterotaxy with or without congenital heart disease, and male infertility, among others. In this report, the carrier frequencies for eleven mutations in eight PCD-associated genes (DNAI1, DNAI2, DNAH5, DNAH11, CCDC114, CCDC40, CCDC65, and C21orf59) that had been found in individuals of Ashkenazi Jewish descent were investigated in order to advise on including them in existing clinical mutation panels for this population. Results showed relatively high carrier frequencies for the DNAH5 c.7502G>C mutation (0.58%), the DNAI2 c.1304G>A mutation (0.50%), and the C21orf59 c.735C>G mutation (0.48%), as well as lower frequencies for mutations in DNAI1, CCDC65, CCDC114, and DNAH11 (0.10–0.29%). These results suggest that several of these genes should be considered for inclusion in carrier screening panels in the Ashkenazi Jewish population.
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cri du chat syndrome and primary ciliary dyskinesia a common genetic cause on chromosome 5p
The Journal of Pediatrics, 2014Co-Authors: Adam J Shapiro, Kay C Chao, Margaret W Leigh, Anders O H Nygren, Karen E Weck, Margaret Rosenfeld, Michael R. Knowles, Maimoona A ZariwalaAbstract:Cri du chat syndrome (CdCS) and primary ciliary dyskinesia (PCD) are rare diseases that present with frequent respiratory symptoms. PCD can be caused by hemizygous DNAH5 mutation in combination with a 5p segmental deletion attributable to CdCS on the opposite chromosome. Chronic oto-sino-pulmonary symptoms or organ laterality defects in CdCS should prompt an evaluation for PCD.
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zmynd10 is mutated in primary ciliary dyskinesia and interacts with lrrc6
American Journal of Human Genetics, 2013Co-Authors: Maimoona A Zariwala, Margaret W Leigh, Heon Yung Gee, Malgorzata Kurkowiak, Dalal A Almutairi, Toby W Hurd, Rim HjeijAbstract:Defects of motile cilia cause primary ciliary dyskinesia (PCD), characterized by recurrent respiratory infections and male infertility. Using whole-exome resequencing and high-throughput mutation analysis, we identified recessive biallelic mutations in ZMYND10 in 14 families and mutations in the recently identified LRRC6 in 13 families. We show that ZMYND10 and LRRC6 interact and that certain ZMYND10 and LRRC6 mutations abrogate the interaction between the LRRC6 CS domain and the ZMYND10 C-terminal domain. Additionally, ZMYND10 and LRRC6 colocalize with the centriole markers SAS6 and PCM1. Mutations in ZMYND10 result in the absence of the axonemal protein components DNAH5 and DNALI1 from respiratory cilia. Animal models support the association between ZMYND10 and human PCD, given that zmynd10 knockdown in zebrafish caused ciliary paralysis leading to cystic kidneys and otolith defects and that knockdown in Xenopus interfered with ciliogenesis. Our findings suggest that a cytoplasmic protein complex containing ZMYND10 and LRRC6 is necessary for motile ciliary function.
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deletions and point mutations of lrrc50 cause primary ciliary dyskinesia due to dynein arm defects
American Journal of Human Genetics, 2009Co-Authors: Niki T Loges, Maimoona A Zariwala, Heike Olbrich, Karsten Haffner, Andreas Kispert, Anita Beckerheck, Angelina Heer, Christina Reinhard, Miriam Schmidts, Margaret W LeighAbstract:Genetic defects affecting motility of cilia and flagella cause chronic destructive airway disease, randomization of left-right body asymmetry, and, frequently, male infertility in primary ciliary dyskinesia (PCD). The most frequent defects involve outer and inner dynein arms (ODAs and IDAs) that are large multiprotein complexes responsible for cilia-beat generation and regulation, respectively. Here, we demonstrate that large genomic deletions, as well as point mutations involving LRRC50, are responsible for a distinct PCD variant that is characterized by a combined defect involving assembly of the ODAs and IDAs. Functional analyses showed that LRRC50 deficiency disrupts assembly of distally and proximally DNAH5- and DNAI2-containing ODA complexes, as well as DNALI1-containing IDA complexes, resulting in immotile cilia. On the basis of these findings, we assume that LRRC50 plays a role in assembly of distinct dynein-arm complexes.
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Genetic Defects in Ciliary Structure and Function
Annual review of physiology, 2007Co-Authors: Maimoona A Zariwala, Michael R. Knowles, Heymut OmranAbstract:AbstractCilia, hair-like structures extending from the cell membrane, perform diverse biological functions. Primary (genetic) defects in the structure and function of sensory and motile cilia result in multiple ciliopathies. The most prominent genetic abnormality involving motile cilia (and the respiratory tract) is primary ciliary dyskinesia (PCD). PCD is a rare, usually autosomal recessive, genetically heterogeneous disorder characterized by sino-pulmonary disease, laterality defects, and male infertility. Ciliary ultrastructural defects are identified in ∼90% of PCD patients and involve the outer dynein arms, inner dynein arms, or both. Diagnosing PCD is challenging and requires a compatible clinical phenotype together with tests such as ciliary ultrastructural analysis, immunofluorescent staining, ciliary beat assessment, and/or nasal nitric oxide measurements. Recent mutational analysis demonstrated that 38% of PCD patients carry mutations of the dynein genes DNAI1 and DNAH5. Increased understanding ...
Rim Hjeij - One of the best experts on this subject based on the ideXlab platform.
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Homozygous loss-of-function mutations in MNS1 cause laterality defects and likely male infertility
PLoS genetics, 2018Co-Authors: Asaf Ta-shma, Dinu Antony, Rim Hjeij, Zeev Perles, Gerard W. Dougherty, Stef J. F. Letteboer, Alaa Darwish, Dorus A. Mans, Ibrahim A. Abu Zahira, Sabrina SpittlerAbstract:The clinical spectrum of ciliopathies affecting motile cilia spans impaired mucociliary clearance in the respiratory system, laterality defects including heart malformations, infertility and hydrocephalus. Using linkage analysis and whole exome sequencing, we identified two recessive loss-of-function MNS1 mutations in five individuals from four consanguineous families: 1) a homozygous nonsense mutation p.Arg242* in four males with laterality defects and infertility and 2) a homozygous nonsense mutation p.Gln203* in one female with laterality defects and recurrent respiratory infections additionally carrying homozygous mutations in DNAH5. Consistent with the laterality defects observed in these individuals, we found Mns1 to be expressed in mouse embryonic ventral node. Immunofluorescence analysis further revealed that MNS1 localizes to the axonemes of respiratory cilia as well as sperm flagella in human. In-depth ultrastructural analyses confirmed a subtle outer dynein arm (ODA) defect in the axonemes of respiratory epithelial cells resembling findings reported in Mns1-deficient mice. Ultrastructural analyses in the female carrying combined mutations in MNS1 and DNAH5 indicated a role for MNS1 in the process of ODA docking (ODA-DC) in the distal respiratory axonemes. Furthermore, co-immunoprecipitation and yeast two hybrid analyses demonstrated that MNS1 dimerizes and interacts with the ODA docking complex component CCDC114. Overall, we demonstrate that MNS1 deficiency in humans causes laterality defects (situs inversus) and likely male infertility and that MNS1 plays a role in the ODA-DC assembly.
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Identification of MNS1 loss-of-function mutations in a PCD-affected individual with DNAH5 mutations.
2018Co-Authors: Asaf Ta-shma, Dinu Antony, Rim Hjeij, Zeev Perles, Gerard W. Dougherty, Ibrahim Abu Zahira, Stef J. F. Letteboer, Alaa Darwish, Dorus A. Mans, Sabrina SpittlerAbstract:(A) Pedigree of families OI-11, OI-14 and OI-24: consanguinity of first degree. In total, five PCD-affected individuals carry homozygous mutations in DNAH5 (annotated as DNAH5mut/mut) of whom only one (OI-11 II6) carries additional homozygous mutations in MNS1 (c.607C>T; p.Gln203*). (B) Bi-allelic MNS1 nonsense mutations in OI-11 II6 (c.607C>T) predicting a premature termination of translation (p.Gln203*). The affected sibling OI-11 II1 and both parents OI-11 I1 and I2 are carriers of the mutant allele. Right panel. Bi-allelic DNAH5 nonsense mutations in OI-11 II6 and OI-11 II1 (c. c.13432_13435delCACT) predicting a premature termination of translation (p.His4478Alafs3*). Both parents OI-11 I1 and I2 are carriers of the mutant allele. (C) Respiratory epithelial cells from control and affected individuals: OI-11 II6 carrying bi-allelic MNS1 and DNAH5 mutations, and OI-24 II1 carrying the identical bi-allelic DNAH5 mutations as OI-11 II6. For space issues, OI-24 II1 is referred to in this and other Figures as DNAH5mut/mut instead of DNAH5c.13432_13435delCACT/ c.13432_13435delCACT. Cells were double-labeled with antibodies directed against acetylated alpha-tubulin (green) and MNS1 (red). Nuclei were stained with Hoechst 33342 (blue). Both proteins co-localize (yellow) along the ciliary axonemes in cells from the unaffected controls and OI-24 II1, while in respiratory cells of OI-11 II6, MNS1 is undetectable in the ciliary axonemes, consistent with recessive loss-of-function MNS1 nonsense mutations. Scale bars, 10μm.
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zmynd10 is mutated in primary ciliary dyskinesia and interacts with lrrc6
American Journal of Human Genetics, 2013Co-Authors: Maimoona A Zariwala, Margaret W Leigh, Heon Yung Gee, Malgorzata Kurkowiak, Dalal A Almutairi, Toby W Hurd, Rim HjeijAbstract:Defects of motile cilia cause primary ciliary dyskinesia (PCD), characterized by recurrent respiratory infections and male infertility. Using whole-exome resequencing and high-throughput mutation analysis, we identified recessive biallelic mutations in ZMYND10 in 14 families and mutations in the recently identified LRRC6 in 13 families. We show that ZMYND10 and LRRC6 interact and that certain ZMYND10 and LRRC6 mutations abrogate the interaction between the LRRC6 CS domain and the ZMYND10 C-terminal domain. Additionally, ZMYND10 and LRRC6 colocalize with the centriole markers SAS6 and PCM1. Mutations in ZMYND10 result in the absence of the axonemal protein components DNAH5 and DNALI1 from respiratory cilia. Animal models support the association between ZMYND10 and human PCD, given that zmynd10 knockdown in zebrafish caused ciliary paralysis leading to cystic kidneys and otolith defects and that knockdown in Xenopus interfered with ciliogenesis. Our findings suggest that a cytoplasmic protein complex containing ZMYND10 and LRRC6 is necessary for motile ciliary function.
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Immunofluorescence microscopy (IFM) analysis of primary ciliary dyskinesia (PCD) patients with suspected inner dynein arm defects (IDA)
Cilia, 2012Co-Authors: Rim Hjeij, Niki T Loges, Anita Becker-heck, Heymut OmranAbstract:Primary ciliary dyskinesia (PCD), characterized by abnormal motility of cilia or flagella, is caused by defects of structural components such as inner dynein arms (IDAs). Recently high-speed videomicroscopy has substituted transmission electron microscopy (TEM) analysis as the “gold standard” for diagnosis. However, TEM is still the most widely used diagnostic tool in many countries. A recent study reported that isolated IDA defects is the most frequent (> 50%) ciliary defect in PCD, as detected by TEM (Theegarten, 2011). IFM analysis has shown in several studies that it can ascertain diagnosis such as in PCD variants caused by DNAH5, DNAI1, DNAI2, KTU, LRRC50, CCDC39 and CCDC40 mutations. IFM can provide a complete view of the ciliary axoneme and identify “partial” axonemal defects which may be misinterpreted by TEM (e.g. present in KTU mutant cilia). Here we performed IFM analysis of known PCD patients to identify the composition of dynein arm defects, including IDAs. Using antibodies specific to the IDA marker DNALI1, we determined that the frequency of isolated IDA defects is unexpected low (thus far, only 12 of ~800 PCD patients, ~1.5%). In contrast, we observe that IDA defects usually accompany DRC defects (absent/abnormal Gas11) or ODA defects (absent/abnormal DNAH5). Because the DNALI1 antibody is targeted against only 3 IDA isoforms out of 7, we are currently screening additional IDA-specific antibodies for IFM analysis to target the other IDA sub-types which escaped our analysis. However, our results suggest the percentage of isolated IDA defects might be lower than previously expected.