ABSTRACT
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.
Subject(s)
Male , Humans , Child , Mutation , Kartagener Syndrome/genetics , Genetic Testing , Mutation, Missense , Exome Sequencing , Axonemal Dyneins/geneticsABSTRACT
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.
Subject(s)
Humans , Chronic Disease , Cilia/pathology , Kartagener Syndrome/genetics , Phenotype , SinusitisABSTRACT
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.
Subject(s)
Humans , Cilia/genetics , Genetic Testing , Kartagener Syndrome/genetics , Sensitivity and SpecificityABSTRACT
Neurofibromatosis (NF) is a genetic disease in which the lungs are rarely involved. However, in NF cases with lung involvement, chest computed tomography may show bilateral basal reticulations, apical bullae, and cysts without bronchiectasis. Herein, we report a patient diagnosed with NF on the basis of the results of genetic testing who presented with early-onset wet cough and bronchiectasis. Considering the differential diagnosis of bronchiectasis combined with his early-onset wet cough, sinusitis, and sperm quality decline, we considered the possibility of primary ciliary dyskinesia (PCD). Further electron microscopy analysis of cilia and identification of homozygous mutations in the RSPH4A gene confirmed the diagnosis of PCD. Therefore, for patients with NF, when an image change exists in the lungs that does not correspond to NF, the possibility of other diagnoses, including PCD, must be considered.
Subject(s)
Humans , Cilia , Kartagener Syndrome/genetics , Microscopy, Electron , Mutation , Neurofibromatosis 1/geneticsABSTRACT
OBJECTIVE@#To explore the genetic basis for a patient with primary ciliary dyskinesia (PCD).@*METHODS@#High-throughput sequencing and bioinformatic analysis were carried out to identify pathogenic variant in the patient. Suspected variant was verified by Sanger sequencing among the family members, and intracytoplasmic sperm injection (ICSI) was used to achieve the pregnancy.@*RESULTS@#The patient had obstructive azoospermia, measurement of nasal NO exhalation at 84 ppb, and typical symptoms of PCD in nasal sinuses and lungs. DNA sequencing showed that he had carried biallelic variants of the DNAH5 gene, namely c.1489C>T (p.Q497X) in exon 11 and c.6304C>T (p.R2102C) in exon 38. His wife achieved clinical pregnancy with the assistance of ICSI.@*CONCLUSION@#Above finding has enriched the spectrum of DNAH5 gene variants, though the latters did not affect the outcome of pregnancy by ICSI.
Subject(s)
Humans , Male , Axonemal Dyneins/genetics , Exons , High-Throughput Nucleotide Sequencing , Kartagener Syndrome/genetics , Sequence Analysis, DNA , Sperm Injections, IntracytoplasmicABSTRACT
Primary ciliary dyskinesia is a congenital disorder due to abnormal motile ciliary function, especially in the airway epithelium. The mucociliary clearance is impaired, producing reoccurring respiratory tract infections, usually resulting in bronchiectasis as an adult. Patients also have frequent ear and sinus infections and almost 50% of them have situs inversus. Diagnosis of primary ciliary dyskinesia is difficult because there is not a single gold standard test, resulting in the need of a multi-test approach. Until recently in our country we only had transmission electron microscopy, but nasal nitric oxide and high speed video microscopy are now available. In this article we will detail the most important clinical characteristics that make us suspect the presence of primary ciliary dyskinesia at different ages and the methods available for its diagnosis.
La discinesia ciliar primaria es una enfermedad congénita debida a una alteración del movimiento normal de los cilios, especialmente a nivel del epitelio respiratorio. Esto se traduce en una alteración del clearance mucociliar lo que predispone al paciente a tener infecciones respiratorias repetidas, terminando en la aparición de bronquiectasias en la edad adulta. También son frecuentes las infecciones repetidas de oídos y cavidades perinasales. La presencia de situs inverso puede verse en hasta en 50% de los pacientes con esta enfermedad. El diagnóstico de discinesia ciliar primaria es difícil ya que no existe un examen que sea considerado patrón de oro, por lo que se requiere la realización de distintos exámenes. En nuestro país hasta hace poco tiempo solo contábamos con la microscopía electrónica, pero recientemente se ha sumado la medición de óxido nítrico nasal y la videomicroscopía de alta velocidad. En el presente artículo se detallarán las características clínicas más importantes que hacen sospechar la presencia de DCP en las distintas edades y los métodos disponibles para su diagnóstico.
Subject(s)
Humans , Infant, Newborn , Child, Preschool , Adult , Kartagener Syndrome/diagnosis , Kartagener Syndrome/genetics , Kartagener Syndrome/therapy , Cilia/ultrastructure , Biopsy , Algorithms , Genetic Testing , Microscopy, Video , Microscopy, Electron, Transmission , Nitric Oxide/analysisABSTRACT
At present, there is no specific treatment for primary ciliary dyskinesia, nor controlled and randomized clinical trials to determine how the management and monitoring of these patients should be considered. The therapeutic options are extrapolated from other diseases, such as cystic fibrosis, or non-cystic fibrosis bronchiectasis. However, the implementation of specific groups of experts, both in the USA (PDC-foundation) and in Europe (BESTCILIA or BEAT-PD), are helping to increase knowledge of the disease, opening research channels and seeking new treatments. Until we have therapies capable of correcting the basic defect of the disease, the pillars of treatment are the daily cleansing of the airways and aggressive antibiotherapy against respiratory infections. Multidisciplinary care in specialized centers where pulmonary function is monitored and the infection is prevented and treated will improve, as in cystic fibrosis, the results of patients.
En la actualidad no existe un tratamiento específico para la discinesia ciliar primaria, ni se cuenta con ensayos clínicos controlados y randomizados que permitan determinar cómo debe plantearse el manejo y seguimiento de estos pacientes. Las opciones terapéuticas son extrapoladas de otras enfermedades, como la fibrosis quística, o las bronquiectasias no fibrosis quística. Sin embargo, la puesta en marcha de grupos específicos de expertos, tanto en USA (PDC-foundation) como en Europa (BESTCILIA o BEAT-PD), están permitiendo incrementar el conocimiento de la enfermedad, abriendo vías de investigación y buscando nuevos tratamientos. Hasta contar con terapias capaces de corregir el defecto básico de la enfermedad, los pilares del tratamiento son la limpieza diaria de las vías aéreas y la antibioterapia agresiva frente a las infecciones respiratorias. La atención multidisciplinar en centros especializados donde se monitorice la función pulmonar y se prevengan y traten las infecciones mejorará, como en la fibrosis quística, los resultados de los pacientes.
Subject(s)
Humans , Kartagener Syndrome/diagnosis , Kartagener Syndrome/physiopathology , Kartagener Syndrome/genetics , Kartagener Syndrome/therapy , Respiratory Tract Infections/drug therapy , Follow-Up Studies , Lung Diseases/physiopathology , Lung Diseases/therapy , Lung Diseases, FungalABSTRACT
Primary ciliary dyskinesia (PCD) is a genetic disorder of ciliary structure or function. It results in mucus accumulation and bacterial colonization of the respiratory tract which leads to chronic upper and lower airway infections, organ laterality defects, and fertility problems. We review the respiratory signs and symptoms of PCD, as well as the screening tests for and diagnostic investigation of the disease, together with details related to ciliary function, ciliary ultrastructure, and genetic studies. In addition, we describe the difficulties in diagnosing PCD by means of transmission electron microscopy, as well as describing patient follow-up procedures.
Discinesia ciliar primária (DCP) é uma doença genética que compromete a estrutura e/ou a função ciliar, causando retenção de muco e bactérias no trato respiratório e levando a infecções crônicas nas vias aéreas superiores e inferiores, defeitos de lateralidade visceral e problemas de fertilidade. Revisamos os sinais e sintomas respiratórios da DCP, os testes de triagem e a investigação diagnóstica, bem como detalhes relacionados ao estudo da função, ultraestrutura e genética ciliar. Descrevemos também as dificuldades em diagnosticar a DCP por meio de microscopia eletrônica de transmissão, bem como o seguimento dos pacientes.
Subject(s)
Humans , Kartagener Syndrome/diagnosis , Axoneme/ultrastructure , Cilia/physiology , Cilia/ultrastructure , Dyneins/ultrastructure , Genetic Diseases, Inborn , Kartagener Syndrome/genetics , Microscopy, Electron , Tomography, X-Ray ComputedABSTRACT
La disquinesia ciliar primaria (DCP) corresponde a una enfermedad genética heterogénea, que se produce por una alteración estructural o funcional de los cilios. Es de difícil diagnóstico tanto por su variada sintomatología como por la existencia de métodos de screening y diagnóstico complejos. El método que hasta ahora ha sido considerado como gold standard es el análisis de la estructura ciliar por medio de la microscopía electrónica de transmisión (MET). Esta técnica tiene limitaciones porque permite analizar un número limitado de axonemas ciliares y puede excluir del diagnóstico a pacientes con axonema normal pero con alteración funcional y clínica clásicas. En los últimos años se han desarrollado métodos diagnósticos sobre la base de un mejor conocimiento de la estructura proteica de los cilios, de los genes que codifican estas proteínas y de las mutaciones asociadas a DCP. Estos nuevos métodos consisten en un análisis genético y un estudio de la expresión de proteínas ciliares en los pacientes afectados. Esta publicación tiene como objetivo realizar una revisión de la fisiopatología de la DCP, los métodos diagnósticos actuales y resumir el desarrollo del diagnóstico genético en la literatura internacional y su posible aplicación en nuestro medio.
Primary cilliary dyskinesia (PCD) is an heterogeneous genetic disease caused by a structural and/or functional alteration of the ciliary skeleton. It is a diagnostic challenge due to its protean clinical presentation and to the complexity of screening and diagnostic methods. The method hitherto regarded as the gold standard is the analysis of ciliary structure by transmission electron microscopy (TEM). This presents limitations because analyzes a limited number of ciliary axonemes, and may exclude cases with typical functional and clinical presentation. In recent years new diagnostic methods have been developed based on novel knowledge of the structural ciliary proteins, the genes encoding these proteins and mutations associated to DCP. These new methods include genetic analysis and the study of protein expression in cilia of the affected patients. This paper reviews DCP pathophysiology, the current diagnostic methods applied, and summarizes the international literature regarding the diagnosis of DCP based on genetic screening.
Subject(s)
Humans , Dyneins/genetics , Kartagener Syndrome/diagnosis , Kartagener Syndrome/physiopathology , Kartagener Syndrome/genetics , Mutation , Genetic Testing , Ciliary Motility Disorders/diagnosis , Ciliary Motility Disorders/physiopathology , Ciliary Motility Disorders/geneticsABSTRACT
Presentamos un caso de Síndrome de Kartagener en un individuo de sexo masculino, 41 años, soltero, trabajador rural, con una historia de más de 20 años de procesos rinosinusales y bronquiales de etiología infecciosa, secreciones nasales purulentas permanentes y espectoración de iguales características. Disnea de esfuerzo en progresión y episodios de exacerberación de la disnea con ruidos endobronquiales configurando una verdadera hiperreactividad bronquial. Los estudios revelaron bronquiectasias masivas en ambos pulmones, insuficiencia ventilatoria mixta, sinusitis, situs inversus total, disquinesia ciliar (test de sacarina) e inmovilidad espermática
Subject(s)
Humans , Male , Adult , Ciliary Motility Disorders/diagnosis , Infertility, Male/etiology , Saccharin , Kartagener Syndrome/diagnosis , Situs Inversus/complications , Bronchiectasis , Bronchiectasis/diagnosis , Kartagener Syndrome/complications , Kartagener Syndrome/genetics , Situs Inversus , Situs Inversus/diagnosisABSTRACT
A Síndrome de Kartagener é determinada pela tríade de situs inversus bronquiectasia e sinusite. Seu substrato anatomo-funcional é uma alteraçäo na ultra-estrutura dos cílio e flagelos, que se tornam discinéticos. Como resultados, todos os epitélios ciliados, bem como os espermatozóides têm sua funçäo prejudicada. Faz-se uma revisäo sobre a Síndrome de Kartagener, com ênfase especial nos aspectos de etiopatogenia e apresentaçäo clínica em conjunto ao relato de um caso