Humans ; Consanguinity ; Exome Sequencing ; Mutation/genetics* ; Sequence Analysis, DNA ; Ciliary Motility Disorders ; Axonemal Dyneins/genetics*

Objective: To evaluate the value of nasal nitric oxide (nNO) measurement as a diagnostic tool for Chinese patients with primary ciliary dyskinesia (PCD). Methods: This study is a retrospective study. The patients were recruited from those who were admitted to the respiratory Department of Respiratory Medicine, Children's Hospital of Fudan University from March 2018 to September 2022. Children with PCD were included as the PCD group, and children with situs inversus or ambiguus, cystic fibrosis (CF), bronchiectasis, chronic suppurative lung disease and asthma were included as the PCD symptom-similar group. Children who visited the Department of Child health Care and urology in the same hospital from December 2022 to January 2023 were selected as nNO normal control group. nNO was measured during plateau exhalation against resistance in three groups. Mann-Whitney U test was used to analyze the nNO data. The receiver operating characteristic of nNO value for the diagnosis of PCD was plotted and, the area under the curve and Youden index was calculated to find the best cut-off value. Results: nNO was measured in 40 patients with PCD group, 75 PCD symptom-similar group (including 23 cases of situs inversus or ambiguus, 8 cases of CF, 26 cases of bronchiectasis or chronic suppurative lung disease, 18 cases of asthma), and 55 nNO normal controls group. The age of the three groups was respectively 9.7 (6.7,13.4), 9.3 (7.0,13.0) and 9.9 (7.3,13.0) years old. nNO values were significantly lower in children with PCD than in PCD symptom-similar group and nNO normal controls (12 (9,19) vs. 182 (121,222), 209 (165,261) nl/min, U=143.00, 2.00, both P<0.001). In the PCD symptom-similar group, situs inversus or ambiguus, CF, bronchiectasis or chronic suppurative lung disease and asthma were significantly higher than children with PCD (185 (123,218), 97 (52, 132), 154 (31, 202), 266 (202,414) vs. 12 (9,19) nl/min,U=1.00, 9.00, 133.00, 0, all P<0.001). A cut-off value of 84 nl/min could provide the best sensitivity (0.98) and specificity (0.92) with an area under the curve of 0.97 (95%CI 0.95-1.00, P<0.001). Conclusions: nNO value can draw a distinction between patients with PCD and others. A cut-off value of 84 nl/min is recommended for children with PCD.
Humans ; Child ; Adolescent ; Nitric Oxide ; Retrospective Studies ; Cystic Fibrosis ; Bronchiectasis/diagnosis* ; Asthma/diagnosis* ; Hospitals, Pediatric ; Ciliary Motility Disorders/diagnosis*

OBJECTIVE: To explore the clinical characteristics and genetic basis of a child with Kartagener syndrome (KTS). METHODS: Trio-whole exome sequencing was carried out for the child and his parents, and candidate variants were verified by Sanger sequencing. Changes in protein structure due to missense variants were simulated and analyzed, and the Human Splicing Finder 3.0 (HSF 3.0) online platform was used to predict the effect of the variant of the non-coding region. RESULTS: The child had featured bronchiectasis, sinusitis and visceral inversion. Genetic testing revealed that he has harbored compound heterozygous variants of the DNAH5 gene, namely c.5174T>C and c.7610-3T>G. Sanger sequencing confirmed the existence of the variants. The variants were not found in the dbSNP, 1000 Genomes, ExAC, ClinVar and HGMD databases. Protein structural analysis suggested that the c.5174T>C (p.Leu1725Pro) variant may affect the stability of local structure and its biological activity. The results of HSF 3.0 analysis suggested that the c.7610-3T>G variant has probably destroyed a splicing receptor to affect the transcription process. CONCLUSION The compound heterozygous variants of the DNAH5 gene probably underlay the pathogenesis in the child. Above finding may facilitate the understanding of the clinical characteristics and genetic basis of KTS, and further expand the spectrum of DNAH5 gene variants.
Male ; Humans ; Child ; Mutation ; Kartagener Syndrome/genetics* ; Genetic Testing ; Mutation, Missense ; Exome Sequencing ; Axonemal Dyneins/genetics*

OBJECTIVE: To explore the genetic etiology for a Chinese pedigree affected with Meckel syndrome. METHODS: A pedigree with a history of three consecutive adverse pregnancies which presented at the First Affiliated Hospital of Zhengzhou University on August 31, 2017 was selected as the study subject. Clinical data of the pedigree were collected. High-throughput sequencing was carried out to screen for variants of ciliopathy-related genes in the third fetus following induced abortion, and candidate variant was verified by Sanger sequencing. RESULTS: The first pregnancy of the couple had ended as spontaneous abortion, whilst the fetus of the second pregnancy was suspected for having ciliopathy, though no genetic testing was carried out following elected abortion. The fetus of the third pregnancy was suspected for having ciliopathy, and high-throughput sequencing and Sanger sequencing had shown that the fetus had harbored compound heterozygous variants of the TMEM67 gene, including c.978+1G>A from the father and c.1288G>C (p.D430H) from the mother. Based on the guidelines from the American College of Medical Genetics and Genomics (ACMG), the c.978+1G>A was classified as a pathogenic variant (PVS1+PM2_Supporting+PP5), whilst the newly discovered c.1288G>C (p.D430H) was classified as a likely pathogenic variant (PM2_Supporting+PM3+PM5+PP3). CONCLUSION The c.978+1G>A and c.1288G>C (p.D430H) compound heterozygous variants of the TMEM67 gene probably underlay the three consecutive adverse pregnancies suspected for ciliopathy in this pedigree. The discovery of c.1288G>C (p.D430H) has also expanded the mutational spectrum of the TMEM67 gene.
Female ; Pregnancy ; Humans ; Pedigree ; East Asian People ; Ciliary Motility Disorders/genetics* ; Ciliopathies ; Abortion, Spontaneous ; Membrane Proteins/genetics*

Primary ciliary dyskinesia (PCD) is a rare hereditary orphan condition that results in variable phenotypes, including infertility. About 50 gene variants are reported in the scientific literature to cause PCD, and among them, dynein axonemal assembly factor 4 ( DNAAF4 ) has been recently reported. DNAAF4 has been implicated in the preassembly of a multiunit dynein protein essential for the normal function of locomotory cilia as well as flagella. In the current study, a single patient belonging to a Chinese family was recruited, having been diagnosed with PCD and asthenoteratozoospermia. The affected individual was a 32-year-old male from a nonconsanguineous family. He also had abnormal spine structure and spinal cord bends at angles diagnosed with scoliosis. Medical reports, laboratory results, and imaging data were investigated. Whole-exome sequencing, Sanger sequencing, immunofluorescence analysis, hematoxylin-eosin staining, and in silico functional analysis, including protein modeling and docking studies, were used. The results identified DNAAF4 disease-related variants and confirmed their pathogenicity. Genetic analysis through whole-exome sequencing identified two pathogenic biallelic variants in the affected individual. The identified variants were a hemizygous splice site c.784-1G>A and heterozygous 20.1 Kb deletion at the DNAAF4 locus, resulting in a truncated and functionless DNAAF4 protein. Immunofluorescence analysis indicated that the inner dynein arm was not present in the sperm flagellum, and sperm morphological analysis revealed small sperm with twisted and curved flagella or lacking flagella. The current study found novel biallelic variants causing PCD and asthenoteratozoospermia, extending the range of DNAAF4 pathogenic variants in PCD and associated with the etiology of asthenoteratozoospermia. These findings will improve our understanding of the etiology of PCD.
Adult ; Humans ; Male ; Asthenozoospermia/genetics* ; Dyneins/genetics* ; East Asian People ; Kartagener Syndrome/genetics* ; Mutation ; Proteins/genetics* ; Semen/metabolism*

Primary ciliary dyskinesia (PCD) is a congenital, motile ciliopathy with pleiotropic symptoms. Although nearly 50 causative genes have been identified, they only account for approximately 70% of definitive PCD cases. Dynein axonemal heavy chain 10 (DNAH10) encodes a subunit of the inner arm dynein heavy chain in motile cilia and sperm flagella. Based on the common axoneme structure of motile cilia and sperm flagella, DNAH10 variants are likely to cause PCD. Using exome sequencing, we identified a novel DNAH10 homozygous variant (c.589C > T, p.R197W) in a patient with PCD from a consanguineous family. The patient manifested sinusitis, bronchiectasis, situs inversus, and asthenoteratozoospermia. Immunostaining analysis showed the absence of DNAH10 and DNALI1 in the respiratory cilia, and transmission electron microscopy revealed strikingly disordered axoneme 9+2 architecture and inner dynein arm defects in the respiratory cilia and sperm flagella. Subsequently, animal models of Dnah10-knockin mice harboring missense variants and Dnah10-knockout mice recapitulated the phenotypes of PCD, including chronic respiratory infection, male infertility, and hydrocephalus. To the best of our knowledge, this study is the first to report DNAH10 deficiency related to PCD in human and mouse models, which suggests that DNAH10 recessive mutation is causative of PCD.
Humans ; Male ; Animals ; Mice ; Semen/metabolism* ; Dyneins/metabolism* ; Cilia/metabolism* ; Mutation ; Ciliary Motility Disorders/genetics*

Primary ciliary dyskinesia (PCD) is a highly heterogeneous recessive inherited disorder. FAP54, the homolog of CFAP54 in Chlamydomonas reinhardtii, was previously demonstrated as the C1d projection of the central microtubule apparatus of flagella. A Cfap54 knockout mouse model was then reported to have PCD-relevant phenotypes. Through whole-exome sequencing, compound heterozygous variants c.2649_2657delinC (p. E883Dfs*47) and c.7312_7313insCGCAGGCTGAATTCTTGG (p. T2438delinsTQAEFLA) in a new suspected PCD-relevant gene, CFAP54, were identified in an individual with PCD. Two missense variants, c.4112A>C (p. E1371A) and c.6559C>T (p. P2187S), in CFAP54 were detected in another unrelated patient. In this study, a minigene assay was conducted on the frameshift mutation showing a reduction in mRNA expression. In addition, a CFAP54 in-frame variant knock-in mouse model was established, which recapitulated the typical symptoms of PCD, including hydrocephalus, infertility, and mucus accumulation in nasal sinuses. Correspondingly, two missense variants were deleterious, with a dramatic reduction in mRNA abundance from bronchial tissue and sperm. The identification of PCD-causing variants of CFAP54 in two unrelated patients with PCD for the first time provides strong supportive evidence that CFAP54 is a new PCD-causing gene. This study further helps expand the disease-associated gene spectrum and improve genetic testing for PCD diagnosis in the future.
Mice ; Animals ; Humans ; Male ; Kartagener Syndrome/metabolism* ; Cilia/metabolism* ; Semen ; Genetic Testing ; RNA, Messenger ; Mutation

Abetalipoproteinemia ; Cilia ; Humans ; Kartagener Syndrome

Primary ciliary dyskinesia (PCD) is a hereditary disease characterized by airway mucociliary clearance dysfunction. The estimated prevalence of PCD is 1꞉10 000 to 1꞉20 000. The main respiratory manifestations in children are cough, expectoration, chronic rhinitis, sinusitis, and chronic otitis media, while the most common symptoms in adults are chronic sinusitis, bronchiectasis, and infertility. About 50% of patients with certain PCD-related gene variants are combined with situs inversus, and the incidence of congenital heart disease is also high. The pathogenesis behind PCD is that gene variants cause structural or functional disorders of respiratory cilia and motile cilia of other organs, leading to a series of heterogeneous clinical manifestations, which makes it difficult to identify and diagnose PCD. Combining different disease screening tools and understanding the relationship between genotypes and phenotypes may facilitate early diagnosis and treatment for PCD.
Chronic Disease ; Cilia/pathology* ; Humans ; Kartagener Syndrome/genetics* ; Phenotype ; Sinusitis

Primary ciliary dyskinesia (PCD) is a recessive genetic disorder of motile cilia with substantial genetic and phenotypic heterogeneity. Clinical features of PCD vary from one patient to another, and no single test has the sensitivity and specificity to accurately diagnose PCD. Genetic testing combined with other auxiliary tests can facilitate the confirmatory diagnosis of PCD. So far more than 40 genes have been associated with PCD, but most research have focused on common genes, which hinders our understanding of other rare PCD-genes. This review has summarized the PCD-associated genes and the corresponding characteristics of dysfunctional cilia, with an aim to provide a basis for early identification of such diseases.
Cilia/genetics* ; Genetic Testing ; Humans ; Kartagener Syndrome/genetics* ; Sensitivity and Specificity