@article {772, title = {Cytoplasmic "ciliary inclusions" in isolation are not sufficient for the diagnosis of primary ciliary dyskinesia.}, journal = {Pediatr Pulmonol}, volume = {55}, year = {2020}, month = {2020 01}, pages = {130-135}, abstract = {

BACKGROUND: The diagnosis of primary ciliary dyskinesia (PCD) is difficult and requires a combination of clinical features, nasal nitric oxide testing, cilia ultrastructural analysis by electron microscopy (EM), and genetics. A recently described cytoplasmic ultrastructural change termed "ciliary inclusions" was reported to be diagnostic of PCD; however, no supporting evidence of PCD was provided. In this study, we sought to confirm, or refute, the diagnosis of PCD in subjects with "ciliary inclusions" on EM.

METHODS: Six subjects from five families with previous lab reports of "ciliary inclusions" on EMs of ciliated cells were identified and evaluated at a Genetic Disorders of Mucociliary Clearance Consortium site. We performed a detailed clinical history, nasal nitric oxide measurement, genetic testing including whole-exome sequencing (WES), and when possible, repeat ciliary EM study.

RESULTS: Only one of six subjects had multiple and persistent clinical features congruent with PCD. No subject had situs inversus. Only one of six subjects had a very low nasal nitric oxide level. No "ciliary inclusions" were found in three subjects who had a repeat ciliary EM, and ciliary axonemal ultrastructures were normal. Genetic testing, including WES, was negative for PCD-causing genes, and for pathogenic variants in gene pathways that might cause "ciliary inclusions," such as ciliary biogenesis.

CONCLUSION: "Ciliary Inclusions", in isolation, are not sufficient to diagnosis PCD. If seen, additional studies should be done to pursue an accurate diagnosis.

}, keywords = {Child, Preschool, Cilia, Ciliary Motility Disorders, Female, Genetic Testing, Humans, Infant, Male, Nasal Mucosa, Nitric Oxide, Whole Exome Sequencing}, issn = {1099-0496}, doi = {10.1002/ppul.24528}, author = {Vece, Timothy J and Sagel, Scott D and Zariwala, Maimoona A and Sullivan, Kelli M and Burns, Kimberlie A and Dutcher, Susan K and Yusupov, Roman and Leigh, Margaret W and Knowles, Michael R} } @article {704, title = {Identification of genetic variants in CFAP221 as a cause of primary ciliary dyskinesia.}, journal = {J Hum Genet}, volume = {65}, year = {2020}, month = {2020 Jan}, pages = {175-180}, abstract = {

Primary ciliary dyskinesia (PCD) is a rare disorder that affects the biogenesis or function of motile cilia resulting in chronic airway disease. PCD is genetically and phenotypically heterogeneous, with causative mutations identified in over 40 genes; however, the genetic basis of many cases is unknown. Using whole-exome sequencing, we identified three affected siblings with clinical symptoms of PCD but normal ciliary structure, carrying compound heterozygous loss-of-function variants in CFAP221. Computational analysis suggests that these variants are the most damaging alleles shared by all three siblings. Nasal epithelial cells from one of the subjects demonstrated slightly reduced beat frequency (16.5 Hz vs 17.7 Hz, p = 0.16); however, waveform analysis revealed that the CFAP221 defective cilia beat in an aberrant circular pattern. These results show that genetic variants in CFAP221 cause PCD and that CFAP221 should be considered a candidate gene in cases where PCD is suspected but cilia structure and beat frequency appear normal.

}, keywords = {Alleles, Calmodulin-Binding Proteins, Cilia, Ciliary Motility Disorders, Epithelial Cells, Exons, Genetic Variation, Humans, Mutation, Proteins, Whole Exome Sequencing}, issn = {1435-232X}, doi = {10.1038/s10038-019-0686-1}, author = {Bustamante-Marin, Ximena M and Shapiro, Adam and Sears, Patrick R and Charng, Wu-Lin and Conrad, Donald F and Leigh, Margaret W and Knowles, Michael R and Ostrowski, Lawrence E and Zariwala, Maimoona A} } @article {807, title = {Mutation of CFAP57, a protein required for the asymmetric targeting of a subset of inner dynein arms in Chlamydomonas, causes primary ciliary dyskinesia.}, journal = {PLoS Genet}, volume = {16}, year = {2020}, month = {2020 08}, pages = {e1008691}, abstract = {

Primary ciliary dyskinesia (PCD) is characterized by chronic airway disease, reduced fertility, and randomization of the left/right body axis. It is caused by defects of motile cilia and sperm flagella. We screened a cohort of affected individuals that lack an obvious axonemal defect for pathogenic variants using whole exome capture, next generation sequencing, and bioinformatic analysis assuming an autosomal recessive trait. We identified one subject with an apparently homozygous nonsense variant [(c.1762C>T), p.(Arg588*)] in the uncharacterized CFAP57 gene. Interestingly, the variant results in the skipping of exon 11 (58 amino acids), which may be due to disruption of an exonic splicing enhancer. In normal human nasal epithelial cells, CFAP57 localizes throughout the ciliary axoneme. Nasal cells from the PCD patient express a shorter, mutant version of CFAP57 and the protein is not incorporated into the axoneme. The missing 58 amino acids include portions of WD repeats that may be important for loading onto the intraflagellar transport (IFT) complexes for transport or docking onto the axoneme. A reduced beat frequency and an alteration in ciliary waveform was observed. Knockdown of CFAP57 in human tracheobronchial epithelial cells (hTECs) recapitulates these findings. Phylogenetic analysis showed that CFAP57 is highly conserved in organisms that assemble motile cilia. CFAP57 is allelic with the BOP2/IDA8/FAP57 gene identified previously in Chlamydomonas reinhardtii. Two independent, insertional fap57 Chlamydomonas mutant strains show reduced swimming velocity and altered waveforms. Tandem mass tag (TMT) mass spectroscopy shows that FAP57 is missing, and the "g" inner dyneins (DHC7 and DHC3) and the "d" inner dynein (DHC2) are reduced, but the FAP57 paralog FBB7 is increased. Together, our data identify a homozygous variant in CFAP57 that causes PCD that is likely due to a defect in the inner dynein arm assembly process.

}, keywords = {3T3 Cells, Adult, Animals, Axoneme, Cells, Cultured, Chlamydomonas reinhardtii, Cilia, Ciliary Motility Disorders, Codon, Nonsense, Conserved Sequence, Dyneins, Humans, Male, Mice, Microtubule-Associated Proteins, Plant Proteins, Proteins, Respiratory Mucosa}, issn = {1553-7404}, doi = {10.1371/journal.pgen.1008691}, author = {Bustamante-Marin, Ximena M and Horani, Amjad and Stoyanova, Mihaela and Charng, Wu-Lin and Bottier, Mathieu and Sears, Patrick R and Yin, Wei-Ning and Daniels, Leigh Anne and Bowen, Hailey and Conrad, Donald F and Knowles, Michael R and Ostrowski, Lawrence E and Zariwala, Maimoona A and Dutcher, Susan K} } @article {583, title = {Lack of GAS2L2 Causes PCD by Impairing Cilia Orientation and Mucociliary Clearance.}, journal = {Am J Hum Genet}, volume = {104}, year = {2019}, month = {2019 02 07}, pages = {229-245}, abstract = {

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.Val296Glyfs13), 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.

}, keywords = {Animals, Cilia, Ciliary Motility Disorders, Disease Models, Animal, Exons, Female, Gene Deletion, Genes, Lethal, Humans, Male, Mice, Mice, Knockout, Microfilament Proteins, Microtubule-Associated Proteins, Phenotype, Rotation, Xenopus}, issn = {1537-6605}, doi = {10.1016/j.ajhg.2018.12.009}, author = {Bustamante-Marin, Ximena M and Yin, Wei-Ning and Sears, Patrick R and Werner, Michael E and Brotslaw, Eva J and Mitchell, Brian J and Jania, Corey M and Zeman, Kirby L and Rogers, Troy D and Herring, Laura E and Refab{\'e}rt, Luc and Thomas, Lucie and Amselem, Serge and Escudier, Estelle and Legendre, Marie and Grubb, Barbara R and Knowles, Michael R and Zariwala, Maimoona A and Ostrowski, Lawrence E} } @article {608, title = {Primary Ciliary Dyskinesia: Longitudinal Study of Lung Disease by Ultrastructure Defect and Genotype.}, journal = {Am J Respir Crit Care Med}, volume = {199}, year = {2019}, month = {2019 01 15}, pages = {190-198}, abstract = {

RATIONALE: In primary ciliary dyskinesia, factors leading to disease heterogeneity are poorly understood.

OBJECTIVES: To describe early lung disease progression in primary ciliary dyskinesia and identify associations between ultrastructural defects and genotypes with clinical phenotype.

METHODS: This was a prospective, longitudinal (5 yr), multicenter, observational study. Inclusion criteria were less than 19 years at enrollment and greater than or equal to two annual study visits. Linear mixed effects models including random slope and random intercept were used to evaluate longitudinal associations between the ciliary defect group (or genotype group) and clinical features (percent predicted FEV and weight and height z-scores).

MEASUREMENTS AND MAIN RESULTS: A total of 137 participants completed 732 visits. The group with absent inner dynein arm, central apparatus defects, and microtubular disorganization (IDA/CA/MTD) (n = 41) were significantly younger at diagnosis and in mixed effects models had significantly lower percent predicted FEV and weight and height z-scores than the isolated outer dynein arm defect (n = 55) group. Participants with CCDC39 or CCDC40 mutations (n = 34) had lower percent predicted FEV and weight and height z-scores than those with DNAH5 mutations (n = 36). For the entire cohort, percent predicted FEV decline was heterogeneous with a mean (SE) decline of 0.57 (0.25) percent predicted/yr. Rate of decline was different from zero only in the IDA/MTD/CA group (mean [SE], -1.11 [0.48] percent predicted/yr; P = 0.02).

CONCLUSIONS: Participants with IDA/MTD/CA defects, which included individuals with CCDC39 or CCDC40 mutations, had worse lung function and growth indices compared with those with outer dynein arm defects and DNAH5 mutations, respectively. The only group with a significant lung function decline over time were participants with IDA/MTD/CA defects.

}, keywords = {Child, Cilia, Cohort Studies, Female, Genotype, Humans, Kartagener Syndrome, Longitudinal Studies, Lung, Male, Mutation, Phenotype, Prospective Studies, Respiratory Function Tests}, issn = {1535-4970}, doi = {10.1164/rccm.201803-0548OC}, author = {Davis, Stephanie D and Rosenfeld, Margaret and Lee, Hye-Seung and Ferkol, Thomas W and Sagel, Scott D and Dell, Sharon D and Milla, Carlos and Pittman, Jessica E and Shapiro, Adam J and Sullivan, Kelli M and Nykamp, Keith R and Krischer, Jeffrey P and Zariwala, Maimoona A and Knowles, Michael R and Leigh, Margaret W} } @article {262, title = {Laterality defects other than situs inversus totalis in primary ciliary dyskinesia: insights into situs ambiguus and heterotaxy.}, journal = {Chest}, volume = {146}, year = {2014}, month = {2014 Nov}, pages = {1176-1186}, abstract = {

BACKGROUND: Motile cilia dysfunction causes primary ciliary dyskinesia (PCD), situs inversus totalis (SI), and a spectrum of laterality defects, yet the prevalence of laterality defects other than SI in PCD has not been prospectively studied.

METHODS: In this prospective study, participants with suspected PCD were referred to our multisite consortium. We measured nasal nitric oxide (nNO) level, examined cilia with electron microscopy, and analyzed PCD-causing gene mutations. Situs was classified as (1) situs solitus (SS), (2) SI, or (3) situs ambiguus (SA), including heterotaxy. Participants with hallmark electron microscopic defects, biallelic gene mutations, or both were considered to have classic PCD.

RESULTS: Of 767 participants (median age, 8.1 years, range, 0.1-58 years), classic PCD was defined in 305, including 143 (46.9\%), 125 (41.0\%), and 37 (12.1\%) with SS, SI, and SA, respectively. A spectrum of laterality defects was identified with classic PCD, including 2.6\% and 2.3\% with SA plus complex or simple cardiac defects, respectively; 4.6\% with SA but no cardiac defect; and 2.6\% with an isolated possible laterality defect. Participants with SA and classic PCD had a higher prevalence of PCD-associated respiratory symptoms vs SA control participants (year-round wet cough, P < .001; year-round nasal congestion, P = .015; neonatal respiratory distress, P = .009; digital clubbing, P = .021) and lower nNO levels (median, 12 nL/min vs 252 nL/min; P < .001).

CONCLUSIONS: At least 12.1\% of patients with classic PCD have SA and laterality defects ranging from classic heterotaxy to subtle laterality defects. Specific clinical features of PCD and low nNO levels help to identify PCD in patients with laterality defects.

TRIAL REGISTRY: ClinicalTrials.gov; No.: NCT00323167; URL: www.clinicaltrials.gov.

}, keywords = {Adolescent, Adult, Biopsy, Child, Child, Preschool, Cilia, DNA, DNA Mutational Analysis, Female, Humans, Infant, Infant, Newborn, Kartagener Syndrome, Male, Microscopy, Electron, Transmission, Middle Aged, Mutation, Prevalence, Prospective Studies, Tomography, X-Ray Computed, United States, Young Adult}, issn = {1931-3543}, doi = {10.1378/chest.13-1704}, author = {Shapiro, Adam J and Davis, Stephanie D and Ferkol, Thomas and Dell, Sharon D and Rosenfeld, Margaret and Olivier, Kenneth N and Sagel, Scott D and Milla, Carlos and Zariwala, Maimoona A and Wolf, Whitney and Carson, Johnny L and Hazucha, Milan J and Burns, Kimberlie and Robinson, Blair and Knowles, Michael R and Leigh, Margaret W} } @article {263, title = {Mutations in RSPH1 cause primary ciliary dyskinesia with a unique clinical and ciliary phenotype.}, journal = {Am J Respir Crit Care Med}, volume = {189}, year = {2014}, month = {2014 Mar 15}, pages = {707-17}, abstract = {

RATIONALE: Primary ciliary dyskinesia (PCD) is a genetically heterogeneous recessive disorder of motile cilia, but the genetic cause is not defined for all patients with PCD.

OBJECTIVES: To identify disease-causing mutations in novel genes, we performed exome sequencing, follow-up characterization, mutation scanning, and genotype-phenotype studies in patients with PCD.

METHODS: Whole-exome sequencing was performed using NimbleGen capture and Illumina HiSeq sequencing. Sanger-based sequencing was used for mutation scanning, validation, and segregation analysis.

MEASUREMENTS AND MAIN RESULTS: We performed exome sequencing on an affected sib-pair with normal ultrastructure in more than 85\% of cilia. A homozygous splice-site mutation was detected in RSPH1 in both siblings; parents were carriers. Screening RSPH1 in 413 unrelated probands, including 325 with PCD and 88 with idiopathic bronchiectasis, revealed biallelic loss-of-function mutations in nine additional probands. Five affected siblings of probands in RSPH1 families harbored the familial mutations. The 16 individuals with RSPH1 mutations had some features of PCD; however, nasal nitric oxide levels were higher than in patients with PCD with other gene mutations (98.3 vs. 20.7 nl/min; P < 0.0003). Additionally, individuals with RSPH1 mutations had a lower prevalence (8 of 16) of neonatal respiratory distress, and later onset of daily wet cough than typical for PCD, and better lung function (FEV1), compared with 75 age- and sex-matched PCD cases (73.0 vs. 61.8, FEV1 \% predicted; P = 0.043). Cilia from individuals with RSPH1 mutations had normal beat frequency (6.1 {\textpm} Hz at 25{\textdegree}C), but an abnormal, circular beat pattern.

CONCLUSIONS: The milder clinical disease and higher nasal nitric oxide in individuals with biallelic mutations in RSPH1 provides evidence of a unique genotype-phenotype relationship in PCD, and suggests that mutations in RSPH1 may be associated with residual ciliary function.

}, keywords = {Adolescent, Adult, Child, Cilia, DNA Mutational Analysis, DNA-Binding Proteins, Exome, Female, Genetic Association Studies, Genetic Markers, Genetic Testing, Homozygote, Humans, Kartagener Syndrome, Linear Models, Male, Middle Aged, Mutation, Nasal Mucosa, Sequence Analysis, DNA, Young Adult}, issn = {1535-4970}, doi = {10.1164/rccm.201311-2047OC}, author = {Knowles, Michael R and Ostrowski, Lawrence E and Leigh, Margaret W and Sears, Patrick R and Davis, Stephanie D and Wolf, Whitney E and Hazucha, Milan J and Carson, Johnny L and Olivier, Kenneth N and Sagel, Scott D and Rosenfeld, Margaret and Ferkol, Thomas W and Dell, Sharon D and Milla, Carlos E and Randell, Scott H and Yin, Weining and Sannuti, Aruna and Metjian, Hilda M and Noone, Peadar G and Noone, Peter J and Olson, Christina A and Patrone, Michael V and Dang, Hong and Lee, Hye-Seung and Hurd, Toby W and Gee, Heon Yung and Otto, Edgar A and Halbritter, Jan and Kohl, Stefan and Kircher, Martin and Krischer, Jeffrey and Bamshad, Michael J and Nickerson, Deborah A and Hildebrandt, Friedhelm and Shendure, Jay and Zariwala, Maimoona A} } @article {296, title = {ARMC4 mutations cause primary ciliary dyskinesia with randomization of left/right body asymmetry.}, journal = {Am J Hum Genet}, volume = {93}, year = {2013}, month = {2013 Aug 08}, pages = {357-67}, abstract = {

The motive forces for ciliary movement are generated by large multiprotein complexes referred to as outer dynein arms (ODAs), which are preassembled in the cytoplasm prior to transport to the ciliary axonemal compartment. In humans, defects in structural components, docking complexes, or cytoplasmic assembly factors can cause primary ciliary dyskinesia (PCD), a disorder characterized by chronic airway disease and defects in laterality. By using combined high resolution copy-number variant and mutation analysis, we identified ARMC4 mutations in twelve PCD individuals whose cells showed reduced numbers of ODAs and severely impaired ciliary beating. Transient suppression in zebrafish and analysis of an ENU mouse mutant confirmed in both model organisms that ARMC4 is critical for left-right patterning. We demonstrate that ARMC4 is an axonemal protein that is necessary for proper targeting and anchoring of ODAs.

}, keywords = {Amino Acid Sequence, Animals, Armadillo Domain Proteins, Axoneme, Body Patterning, Cilia, DNA Copy Number Variations, DNA Mutational Analysis, Dyneins, Gene Expression Regulation, Humans, Kartagener Syndrome, Mice, Microtubule-Associated Proteins, Molecular Sequence Data, Mutation, Respiratory System, Zebrafish}, issn = {1537-6605}, doi = {10.1016/j.ajhg.2013.06.009}, author = {Hjeij, Rim and Lindstrand, Anna and Francis, Richard and Zariwala, Maimoona A and Liu, Xiaoqin and Li, You and Damerla, Rama and Dougherty, Gerard W and Abouhamed, Marouan and Olbrich, Heike and Loges, Niki T and Pennekamp, Petra and Davis, Erica E and Carvalho, Claudia M B and Pehlivan, Davut and Werner, Claudius and Raidt, Johanna and K{\"o}hler, Gabriele and H{\"a}ffner, Karsten and Reyes-Mugica, Miguel and Lupski, James R and Leigh, Margaret W and Rosenfeld, Margaret and Morgan, Lucy C and Knowles, Michael R and Lo, Cecilia W and Katsanis, Nicholas and Omran, Heymut} }