1. Introduction
Primary ciliary dyskinesia (PCD, MIM 244400) is an inherited motile ciliopathy disorder characterized by recurrent sinopulmonary infections, subfertility, and laterality defects [1]. PCD is most commonly inherited in an autosomal recessive pattern, but autosomal dominant and X-linked recessive patterns have also been reported [2]. It is individually rare, but is collectively common, with huge impact on the patients’ quality of life as well as morbidity and mortality [3,4,5,6]. Although PCD has been reported in many ethnic groups, the true prevalence is still unknown [7,8,9]. Based on a large international survey of European pediatric PCD patients, the estimated prevalence ranged from 1:10,000 to 1:20,000 live-born children. The true incidence of PCD in Saudi Arabia (SA) is not known, but it is likely underdiagnosed due to the high prevalence of consanguineous marriages [10].
The diagnosis of PCD can be delayed or missed until adulthood due to a lack of awareness of the disease and/or the difficulty in confirming it. It has a spectrum of clinical manifestations that start in the first year of life and progress with time, leading to bronchiectasis and respiratory failure [3,4,11]. The official clinical guidelines of the American Thoracic Society (ATS) for PCD diagnosis state that a further PCD diagnostic work up for patients with two out of the following four criteria is recommended: unexplained neonatal respiratory distress (NRD) in term infants, year-round daily cough beginning before 6 months of age, year-round daily nasal congestion beginning before 6 months of age, and organ laterality defects [12]. Although PCD can manifest in early infancy, the confirmation of the diagnosis is challenging, even in highly specialized PCD centers, due to the lack of a gold-standard test. Based on the North American PCD Foundation, about 10% of people with PCD have been definitively diagnosed and followed up with at a PCD clinical center [13].
Several functional assay tools are used for PCD diagnosis, such as transmission electron microscopy (TEM), high-speed video microscopy, and nasal nitric oxide; however, these tools are complex, expensive, and require special expertise [12,14]. For several years, TEM has been used as the gold-standard diagnostic modality for PCD diagnosis; nevertheless, TEM data are normal in approximately 30% of PCD cases [12,13]. In recent years, there has been growing interest in using genetic testing as the first modality to confirm the diagnosis of PCD in people with a compatible PCD phenotype, especially when other functional tests are not available [13,15]. An ever-increasing body of literatures shows that over 50 genes have been linked to PCD, and the genetic understanding of PCD is evolving as new genes are discovered [13,16,17]. Although there is no cure for PCD, early diagnosis and management are essential for improving long-term lung function [5]. The standard therapy for PCD currently includes regular airway clearance and aggressive antibiotic therapy for pulmonary exacerbations, which is mostly extrapolated from diseases such as cystic fibrosis (CF). However, a proper definition of the PCD phenotype and genotype may introduce the possibility of discovering future mutation-specific therapies, as occurred in CF. Herein, we aim to study the clinical and genetic characteristics of PCD patients in the southwestern region of Saudi Arabia to provide guidance to clinicians and researchers studying PCD.
2. Materials and Methods
2.1. Patients and Study Setting
This was a cross-sectional study conducted between 2019 and 2023 in Abha Maternity and Children’s Hospital. Twenty-eight patients with clinically diagnosed PCD were recruited. Clinical PCD diagnoses were made based on the latest ATS diagnostic guidelines, which require the presence of two out of four of the following criteria: (a) a persistent, wet cough that starts in the first 6 months of life, (b) persistent, nasal congestion that starts in the first 6 months of life, (c) the presence of organ laterality abnormalities, and (d) unexplained NRD in infants born at term gestation [12]. Additionally, all patients completed the PICADAR questionnaire. PICADAR is a clinical score that evaluates the presence of certain symptoms and signs of PCD, such as a daily wet cough that started in infancy, unexplained chest symptoms in the neonatal period, neonatal intensive care admission, situs abnormality, congenital heart disease, persistent year-round rhinitis, and chronic ear or hearing symptoms. PICADAR is a simple clinical prediction score with sensitivity of 90% for a cut-off score of 5 points [18]. Clinical and radiological data were collected from the patients and their caregivers, as well as from their medical records. These data included medical history, physical examination, and imaging findings. A diagnosis of PCD was confirmed by finding two mutations in one or two genes that are known to cause PCD. The diagnosis of chronic rhinosinusitis was based on the presence of 2 or more symptoms of purulent rhinorrhea, nasal obstruction, facial pressure/pain, or a cough and either endoscopic signs of mucosal edema, purulent drainage, or nasal polyposis and/or paranasal sinuses computed tomography (CT) scan changes showing mucosal changes within the ostiomeatal complex and/or sinuses including sinus mucosal thickening, a sinus ostial obstruction, and sinus opacification [19].
2.2. Genetic Testing
The diagnosis of PCD was confirmed via whole-exome sequencing (WES) for all the patients. All molecular genetic studies were performed in accredited commercial laboratories, such as CENTOGENE (
2.3. Radiological Image Acquisition
All the patients underwent chest radiography (CXR) using a Carestream (Carestream Health, Rochester, NY, USA) machine at their first visits. In addition, 17 patients underwent high-resolution chest CT and CT scans of the paranasal sinuses using a 16-slice CT scanner (Siemens Healthcare, Erlangen, Germany). The indications for a chest CT scan were recurrent pulmonary exacerbations and the presence of signs of chronic suppurative lung diseases, such as finger clubbing and chest crackles. CXR and CT films were interpreted by a pediatric radiologist with ten years of experience following passing the medical board exam. CXR and CT films were evaluated for the presence, distribution, and characteristics of consolidation, mucus plug, and bronchiectasis. Changes in the paranasal sinuses on CT scan were assessed for mucosal thickening, the obstruction of the sinus ostia, and the opacification of the sinuses.
2.4. Statistical Analysis
Statistical analysis was performed using Stata version 14 (StataCorp, College Station, TX, USA). Non-normally distributed variables were summarized as median (interquartile range, IQR). Categorical variables were summarized as counts and percentages. The non-parametric Mann–Whitney U test was used to compare non-normally distributed continuous variables. The chi-square test was used to compare categorical variables. A p-value of less than 0.05 was considered statistically significant.
3. Results
3.1. Clinical Phenotyping of the Study Population
A total of 28 patients from 20 families were identified and recruited for this study. The baseline clinical characteristics, including neonatal history, presenting symptoms, and growth parameters, are summarized in Table 1. The median age of patients was 7.5 years (IQR = 3, 13 years). The patients of different sexes were evenly distributed, and 18 patients (64%) had NRD and required NICU admission, with a median hospital stay duration of 18 days (IQR = 11, 42 days). The median age of diagnosis was 5.5 years (IQR = 2, 11 years), while the age when the first symptoms appeared was 3 months old (IQR = 1, 6 months). Seven patients (25%) had a sibling with a confirmed diagnosis of PCD, and sixteen patients (57.1%) had a family member with suspected PCD. The consanguinity rate among the enrolled study participants was 93%. The median BMI percentile (%) was 12% (IQR = 3.5, 46th %), and eight patients (28.6%) had a BMI % below the 5th percentile. The median PICADAR score was eight (IQR = 6,12). The prevalence of chronic wet coughs, chronic rhinosinusitis, ear infections were 100% (n = 28), 78.6% (n = 22), and 67.9% (19), respectively. Of the 28 patients with PCD, 64% had situs solitus, and 36% had situs inversus. Overall, 32% of the patients had congenital heart disease, and 21% had pectus excavatum/carinatum (Figure 1).
3.2. Genetics of the Study Population
Table 2 and Figure 2 show the genetic results and the associated phenotypes of the enrolled patients. The most common gene in our study was DNAH5, which represented 17.9% (five out of twenty-eight) of the cases. Furthermore, the remaining pathogenic variants included: 14.3% with RSPH9 in four individuals (three families), 14.3% with DNAI2 in four individuals (two families), 10.7% with LRRC56 in three individuals (one family), 7.1% with DNAI1 in two individuals (one family), 7.1% with DNAH11/DNAH9 in two individuals (two families), 7.1% with SPAG1/RSPH4A in two individuals (one family), 3.6% with SPEF2 in one individual (one family), 3.6% with CCDC151/TP73 in one individual (one family), 3.6% with DNAAF5 in one individual (one family), 3.6% with RSPH4A in one individual (one family), 3.6% with TP73 in one individual (one family), and 3.6% with DNAAF3 in one individual (one family). The genes that were linked to situs inversus totalis include DNAH5, DNAI2, DNAAF5, DNAI1, and LRRC56. Four patients of our study subjects had additional associated anomalies that included hepatic hemangioendothelioma, anorectal malformation, congenital aplastic anemia, and congenital asplenia: the patients’ numbers were 21, 9, 19, and 23, respectively.
3.3. Radiological Findings of the Study Population
The CXR and CT chest findings of the enrolled patients are summarized in Table 3. CXRs were conducted on all 28 patients, and chest CTs were performed on 17 of them. The CXRs showed lobar collapse/consolidation in 19 (67.9%) and peribronchial wall thickening in 24 (85.7%) of the patients. The most common findings on chest CT scans were consolidation (seen in all patients), mucus plugging (seen in 95%), bronchiectasis (seen in 77%), and ground-glass density (seen in 36%). In patients with bronchiectasis, the most commonly affected lobes were the right lower lobe (88%), left lower lobe (76%), right middle lobe (65%), left upper lobe (47%), and right upper lobe (29%). Selected CT chest findings for some of the enrolled patients are shown in Figure 3.
3.4. Characteristics of PCD in Patients with and without Situs Inversus
Table 4 reveals the characteristics of PCD in the patients with situs solitus and situs inversus. The PCD patients with situs inversus compared to those with PCD with situs solitus did not differ in terms of age at the time of the study, age at the time of the diagnosis, duration of NICU admission, BMI percentile, and the prevalence of bronchiectasis. However, the median age of symptom onset was slightly higher in the patients with PCD and situs solitus (median: 4 months; Q1: 2–Q3: 7 months) than it was in the patients with PCD and situs inversus (median: 1 month; Q1: 0–Q3: 5 months). This difference was marginally significant (Mann–Whitney U test, U = 55, p = 0.090). A chi-square test was performed to examine the association between NRD and laterality defects (situs inversus and situs solitus). The association between these variables was significant; X2 (1, n = 28) = 4.5, p = 0.040. The patients with PCD and situs inversus were more likely to experience NRD than the patients with PCD and situs solitus were. The median PICADAR score in the patients with PCD and situs inversus (median: 11.5; Q1: 10–Q3: 12.5) was significantly higher compared to those with PCD and situs solitus (median: 7.5; Q1: 5.8–Q3: 8) (U = 10.5; p < 0.001).
4. Discussion
Since the discovery of the first PCD-associated gene in 2000 [22], PCD has remained a heterogeneous disease with poor phenotype–genotype correlation [23]. Despite the symptoms of PCD appearing in early infancy [14,24], diagnosis is often delayed [1,25,26,27]. Until recently, TEM was the gold-standard diagnostic test for PCD, but it was only available in a few specialized centers. Herein, we aimed to study the clinical and genetic features of patients with PCD in the southwestern region of Saudi Arabia. To our knowledge, this is the first study to describe the clinical and genetic features of PCD patients in this region. Twenty-eight patients with classic symptoms of PCD and evidence of two mutations in genes associated with PCD were reported. The genes involved were CCDC151, DNAAF3, DNAAF5, DNAH11, DNAH5, DNAH9, DNAI1, DNAI2, LRRC56, RSPH4A, RSPH9, SPAG1, SPEF2, and TP73. These genes are essential to produce proteins that are important for the structural and functional integrity of cilia. The proteins they produce include components of the outer dynein arms ((ODA) and (DNAI1, DNAI2, DNAH5, DNAH9, and DNAH11)), a component of the ODA docking complex (CCDC151), an assembly of ODA and IDA complexes (DNAAF3, SPAG1, and DNAAF5), a component of the central sheath (SPEF2), components of the radial spoke (RSPH4A and RSPH9), and the absence of ODA in a distal portion of the axoneme (LRRC56) [1]. The phenotype of these gene defects is largely determined by the respiratory manifestations, which are present at all ages.
Although our findings revealed that the symptoms can appeared as early as 3 months of age, the median age of diagnosis was 5.5 years. In accordance with the present results, previous studies have demonstrated that mean age of PCD diagnosis was 4.4–6 years [24,28]. A delay in diagnosis can have a significant impact on the patients’ long-term pulmonary manifestation, as it can lead to decline in lung function and bronchiectasis [3]. The explanation for delayed diagnosis is likely due to the overlapping between PCD symptoms and other diseases such as asthma, protracted bacterial bronchitis, CF, and aerodigestive disorders. Additionally, the lack of awareness of this disease could contribute to this diagnosis delay. In this study, we followed the latest ATS diagnostic guidelines, which require the presence of PCD features before ordering a confirmation test. We found that the prevalence of a chronic wet cough, chronic rhinosinusitis, ear infections, and situs inversus was 100%, 78.6%, 67.9%, and 36%, respectively. Furthermore, 18 patients (64%) had NRD. The findings of our study corroborate the existing literature that state that these manifestations are prevalent in PCD patients [1,8,29,30]. The findings of our study are in line with those of Alzaid et al. (2021), who also found that all 18 enrolled patients with PCD reported a history of chronic coughs and chronic sinusitis [31]. Notably, the prevalence of consanguineous marriages in this population was high, at 93%. It is worth noting that consanguinity is common in the Saudi population [10], which could partly explain the high prevalence of autosomal recessive disorders [32]. The findings of this study suggest that the actual prevalence of PCD, especially in populations with high levels of consanguinity, is underestimated and could be higher than previously thought compared to those of other countries that have PCD registries and estimated PCD prevalence levels. Therefore, it is essential to increase the awareness among clinicians about the PCD symptoms and the importance of early diagnosis, with the highest level of awareness needed among healthcare workers at the primary healthcare level.
PCD is one of the airway clearance disorders that is caused by ciliopathy, which involve multiple organs or systems, especially in the respiratory tract [15,30]. So far, over 50 genes have been reported as disease-causing for PCD [15]. In our study, the DNAH5 gene, which encodes a dynein protein that is part of a microtubule-associated motor protein complex, was the most common gene. This finding is consistent with the findings of other studies in this area, which have also reported that DNAH5 is the most common gene in PCD patients. Zhao et al. (2021) found that DNAH5 was the most prevalent disease-causing gene in 23.1% of 26 patients with PCD of Chinese origin [8]. Moreover, DNAH5 was also the most prevalent gene among a PCD cohort from Turkey that represented 26.1% (12 out of 46 individuals) [25]. On the contrary, two recent studies reported from Saudi Arabia found that RSPH9 was the most common gene identified [31,33]. Furthermore, our finding is contrary to previous studies which have found that CCDC39 and CCDC40 are the most prevalent mutated genes in individuals with PCD of Egyptian and Tunisia origin [34,35]. The results of these studies, including our own, should be interpreted with caution due to the small sample sizes and the fact that they were all conducted in tertiary hospitals. These factors may have biased the results and preventing the accurate estimation of these genes prevalence among all PCD patients. Additionally, the occurrence of genetic variations among these studies may add to the complexity of PCD genetics in the Arab population. This necessitates further collaboration between healthcare centers and pediatric pulmonologists to promptly identify PCD patients and provide appropriate counseling.
In our study cohort, 17 out of 22 patients who had a chest CT scan had bronchiectasis, and all of them were over 8 years old. Furthermore, our results demonstrated that lower lobes were the most commonly involved lobes. In contrast to CF, data from several studies have revealed that the structural lung damage in PCD patients starts later and progresses slowly [36]. Cohen-Cymberknoh et al. studied the structural lung damage in PCD patients compared with CF patients using high-resolution CT, with the calculation of the total Brody scores (TBSs) [37]. The Brody score is a validated score for assessment of presence and severity of structural lung damage in patients with CF [38]. Using the TBS, they found that PCD lung disease was similar to CF pancreatic sufficient (CF-PS) (TBS of 30.8 for PCD vs. 31.4 for CF-PS) lung damage, but it differs in CF pancreatic insufficient (CF-PI) (TBS of 57.3, P, 0.001). Moreover, they found that the lower lobes are commonly involved in PCD as compared to CF; the upper lobes are usually spared in PCD. When they correlated the TBS with the forced expiratory volume at one second (FEV 1), they found that no correlation was seen between FEV 1 and TBS in PCD (r = 0.08, p = 0.71) [37]. It is important to note that our findings rely on a single CT scan, and for sure, further longitudinal studies are needed to precisely identify the radiological progression of the structural lung damage, the predictors of PCD structural lung damage, and the trajectories of spirometry measures.
Although it is estimated that about half of PCD patients have situs inversus (Kartagener’s syndrome) or other laterality defects, our study found a frequency of 36%. A total of 36% of situs inversus cases in our study were associated with the following genes: DNAH5, DNAI1, DNAI2, DNAAF5, and LRRC56. The lower prevalence of laterality defects in our study compared to what is known in the literature is likely due to the fact that a number of our patients had mutations in genes that affect the central pair or radial spoke components (RSPH1 and RSPH4), which do not cause left/right body asymmetry [1,4]. After stratifying the enrolled patients by laterality defects, we found that those with situs inversus had a higher PICARD score, a higher prevalence of NRD, and an earlier median age at diagnosis (2.8 years vs. 8.5 years). Other studies have also reported this trend. Kuehni et al. found that patients with PCD and situs inversus were diagnosed an average of 2 years earlier than those without situs inversus (3.5 years vs. 5.8 years; p = 0.001) [11]. A large study of 1375 children with PCD found that 30% were diagnosed within their first year of life: 52% of those with both situs anomalies and NRD, 33% of those with situs anomalies but no NRD, 21% of those with situs solitus and NRD, and 13% of those with situs solitus and no NRD [39]. Taken together, the presence of NRD and laterality defects in early infancy is a red flag for PCD, and clinicians should further evaluate these patients for a diagnosis of PCD.
The findings of this study have to be read in light of some limitations. First, with a small sample size and the absence of functional studies, caution must be applied; therefore, a larger sample size with incorporation of new cilia functional assessment diagnostic tools is required to validate and confirm the current findings. Second, the cross-sectional study design is a limiting factor to study the exact timing of the symptom’s appearance as well as the predictors of bronchiectasis. Nevertheless, these findings, for sure, would enriches the clinical phenotypes and genetic spectrum of PCD, particularly among Saudi patients, and provide more evidence for future genetic counseling and gene-targeted therapy for this disease. Furthermore, in SA, the national PCD registry is lacking, and the available data are only based on case series and case reports. Therefore, a national PCD registry is recommended.
5. Conclusions
To summarize, this study provides preliminary data on the clinical and genetic characteristics of PCD patients in the southwestern region of Saudi Arabia. We found that DNAH5 and RSPH9 genes were the most common genes among the studied population. Furthermore, PCD should be considered in children with early NRD and laterality defects, and further confirmatory tests are recommended. The study has limitations, but we suggest that further clinical and basic studies are needed to delineate the phenotype and genotype of PCD in this population. These findings also highlighting the need for greater awareness of the disease in daily clinical practice to facilitate early diagnosis and avoid irreversible lung damage.
Conceptualization, A.A.A. and A.A.S.; methodology, A.A.A., R.H.A., H.A.A.-A., M.A. and B.G.A.-A.; software, A.A.A. and A.A.S.; validation, A.A.A., H.A.A.-A., M.A. and A.A.S.; formal analysis, A.A.A., A.A.S., I.A.A., R.H.A. and H.A.A.-A.; investigation, A.A.A., H.A.A.-A., M.A. and A.A.S.; resources, A.A.S., I.A.A., R.H.A. and H.A.A.-A.; data curation, R.H.A., H.A.A.-A., M.A., B.G.A.-A. and H.A.; writing—original draft preparation, A.A.A.; writing—review and editing, A.A.A. and A.A.S.; visualization, A.A.A. and A.A.S.; supervision, A.A.A.; project administration, A.A.A.; funding acquisition, A.A.A. All authors have read and agreed to the published version of the manuscript.
The study was approved by the Research Ethics Committee at King Khalid University (HAPO-06-B-001) via approval number (ECM#2023-606) dated 12 January 2023. It was carried out according to the Declaration of Helsinki. Patients’ informed consent was taken prior to data collection.
Written informed consent has been obtained from the patient(s) to publish this paper.
On reasonable request, the corresponding author will provide the datasets used and/or analyzed during the current work.
The authors extend their appreciation to the Ministry of Education in KSA for funding this research work through the project number (KKU-IFP2-H-13). In addition, the authors would like to thank all of the patients and families who contributed to this analysis.
The authors declare no conflict of interest.
Footnotes
Disclaimer/Publisher’s Note: The statements, opinions and data contained in all publications are solely those of the individual author(s) and contributor(s) and not of MDPI and/or the editor(s). MDPI and/or the editor(s) disclaim responsibility for any injury to people or property resulting from any ideas, methods, instructions or products referred to in the content.
Figure 1. Clinical information on signs, symptoms, and comorbidities of the enrolled patients (n = 28). Congenital heart disease was diagnosed based on the echocardiogram results.
Figure 2. Characteristics of primary ciliary dyskinesia genes in the enrolled patients (n = 28). DNAH5 was the most prevalent. Blue color indicates the number of patients in particular gene. Green color indicates the number of patients with situs inversus totalis. Grey color indicates the number of patients with congenital anomalies. Red color indicates the number of patients with neonatal respiratory distress.
Figure 3. CT scans chest findings (patients 17, 12, 16, and 7). (A) CT scan of patient 17 (14-year-old female with RSPH9 gene mutation) shows mosaics pattern with bilateral bronchiectasis. (B) CT scan of the patient 13 (13-year-old female with TP73 gene mutation) shows left lower lobe cystic bronchiectasis. (C) CT scan of the patient 16 (15-year-old male with DNAH5 gene mutation) shows bilateral cystic bronchiectasis. (D) CT scan of the patient 8 (25-year-old female with DNAH5 gene mutation) shows mosaic attenuation with bilateral bronchiectasis.
Baseline characteristics of the patients.
Variable | n = 28 |
---|---|
Age, median (IQR), y | 7.5 (3–13) |
Sex, male, No. (%) | 14 (50) |
Age at diagnosis, (IQR), y | 5.5 (2–11) |
Age at the first symptom appears, median (IQR), months | 3 (1–6) |
Neonatal respiratory distress, No. (%) | 18 (64) |
Duration of hospital stay, median (IQR), days | 18 (11–42) |
Family history of affected members, No. (%) | |
|
7 (25) |
|
16 (57.1) |
|
26 (93) |
Growth parameters | |
|
18 (8–25) |
|
115 (78–128) |
|
15 (12–16) |
|
12 (3.5–46) |
|
8 (28.6) |
PICADAR score | |
|
8 (6–12) |
|
4–14 |
IQR: interquartile range; No.: number; y: year; kg: kilograms; cm: centimeters; BMI: body mass index.
Genetic variants of the patients (n = 28).
Family No. | Patient No. | Gene | DNA Change | Amino Acid Change | OMIM |
---|---|---|---|---|---|
1 | 1 | RSPH9 | c.804_806del | NA | 612648 |
2 | RSPH9 | c.804_806del | NA | 612648 | |
2 | 3 | DNAH5 | c.877dup | p.Arg293fs | NA |
3 | 4 | DNAI2 | c.1631_1632insAGCG | NA | 605483 |
5 | DNAI2 | c.1631_1632insAGCG | NA | 605483 | |
6 | DNAI2 | c.1631_1632insAGCG | NA | 605483 | |
4 | 7 | DNAH5 | c.6763C>T | p.Arg2255Ter | 603335 |
8 | DNAH5 | c.6763C>T | p.Arg2255Ter | 603335 | |
5 | 9 | RSPH4A/SPAG1 | c.1547C>T/c.1180G>A | p.Ala516Val/p.Glu394Lys | 612647/603395 |
10 | RSPH4A/SPAG1 | c.1547C>T/c.1180G>A | p.Ala516Val/p.Glu394Lys | 612647/603395 | |
6 | 11 | SPEF2 | c.3063G>C | p.Glu1021Asp | NA |
7 | 12 | DNAAF3 | c.1513G>T | p.Gly505Ter | 614566 |
8 | 13 | TP73 | c.1342G>A | p.Val448Met | 601990 |
9 | 14 | DNAH11/DNAH9 | c.11839+1G>A/c.6457G>A | -/p.Ala2153Thr | 603339/603330 |
10 | 15 | RSPH4A | c.1547C>T | p.Ala516Val | 612647 |
11 | 16 | DNAH5 | c.877dup | NA | NA |
12 | 17 | RSPH9 | c.825G>C | p.Met275lle | 612648 |
13 | 18 | RSPH9 | c.804_806del | p.K268del | 612650 |
14 | 19 | DNAAF5 | c.2200delG | p.G734fs | 614874 |
15 | 20 | CCDC151/TP73 | c.556A>G/c.1612C>T | p.Ser186Gly/p.Arg538Cys | 615956/601990 |
16 | 21 | DNAH11/DNAH9 | c.4775G>T/c.3386G>T | p.Cys1592Phe/p.Ser1129Ile | 603339/603330 |
17 | 22 | DNAH5 | c.877dup | p.Arg293fs | NA |
18 | 23 | DNAI1 | c.1228G>A | p.G4105 | 244400 |
24 | DNAI1 | c.1228G>A | p.G4105 | 244400 | |
19 | 25 | DNAI2 | c.1408G>A | p.Gly470Ser | 605483 |
20 | 26 | LRRC56 | c.494T>C | p.Leu165Pro | 618254 |
27 | LRRC56 | c.494T>C | p.Leu165Pro | 618254 | |
28 | LRRC56 | c.494T>C | p.Leu165Pro | 618254 |
Chest radiograph and CT scan findings of the enrolled patients.
Variable | n = 28 |
---|---|
Chest Radiograph findings, No. (%) | |
|
19 (68) |
|
24 (86) |
CT scan findings (n = 22), No. (%) | |
|
17 (77) |
|
21 (95) |
|
22 (100) |
|
8 (36) |
Distribution of bronchiectasis (n = 17), No. (%) | |
|
11 (65) |
|
8 (47) |
|
5 (29) |
|
8 (47) |
|
15 (88) |
|
13 (76) |
Characteristics of primary ciliary dyskinesia in patients with situs solitus and situs inversus.
Variables | Situs Solitus |
Situs Inversus |
χ2/U | p-Value |
---|---|---|---|---|
Age at the time of study, median, y | 9 | 5 | 69.5 | 0.324 |
Age at the time of diagnosis, median, y | 8.5 | 2.8 | 58 | 0.124 |
Age at the first symptom appears, median, months | 4 | 1 | 55 | 0.090 |
Neonatal respiratory distress, n | 9 | 9 | 4.48 | 0.040 |
Duration of NICU admission, days | 14 | 31.5 | 30 | 0.563 |
BMI percentile for age, median | 10 | 15 | 56 | 0.269 |
PICADAR score, median | 7.5 | 11.5 | 10.5 | <0.001 |
Bronchiectasis, n | 13 | 4 | 2.8 | 0.103 |
χ2: Chi-square test; U: Mann–Whitney U test; N: number; n: number; y: year; NICU: neonatal intensive care unit; BMI: body mass index. Statistical significance p < 0.05.
References
1. Mirra, V.; Werner, C.; Santamaria, F. Primary ciliary dyskinesia: An update on clinical aspects, genetics, diagnosis, and future treatment strategies. Front. Pediatr.; 2017; 5, 135. [DOI: https://dx.doi.org/10.3389/fped.2017.00135]
2. Collins, S.; Walker, W.; Lucas, J. Genetic Testing in the Diagnosis of Primary Ciliary Dyskinesia: State-of-the-Art and Future Perspectives. J. Clin. Med.; 2014; 3, pp. 491-503. [DOI: https://dx.doi.org/10.3390/jcm3020491]
3. Halbeisen, F.S.; Goutaki, M.; Spycher, B.D.; Amirav, I.; Behan, L.; Boon, M.; Hogg, C.; Casaulta, C.; Crowley, S.; Haarman, E.G. et al. Lung function in patients with primary ciliary dyskinesia: An iPCD Cohort study. Eur. Respir. J.; 2018; 52, 1801040. [DOI: https://dx.doi.org/10.1183/13993003.01040-2018] [PubMed: https://www.ncbi.nlm.nih.gov/pubmed/30049738]
4. Tinoco, E.M.; Gigante, A.R.; Ferreira, E.; Sanches, I.; Pereira, R.; Sá, R.; Monteiro, R.; Sousa, M.; Pascoal, I. Primary Ciliary Dyskinesia in a Portuguese Bronchiectasis Outpatient Clinic. Genes; 2023; 14, 541. [DOI: https://dx.doi.org/10.3390/genes14030541] [PubMed: https://www.ncbi.nlm.nih.gov/pubmed/36980814]
5. Leigh, M.W.; Pittman, J.E.; Carson, J.L.; Ferkol, T.W.; Dell, S.D.; Davis, S.D.; Knowles, M.R.; Zariwala, M.A. Clinical and genetic aspects of primary ciliary dyskinesia/kartagener syndrome. Genet. Med.; 2009; 11, pp. 473-487. [DOI: https://dx.doi.org/10.1097/GIM.0b013e3181a53562] [PubMed: https://www.ncbi.nlm.nih.gov/pubmed/19606528]
6. Mullowney, T.; Manson, D.; Kim, R.; Stephens, D.; Shah, V.; Dell, S. Primary ciliary dyskinesia and neonatal respiratory distress. Pediatrics; 2014; 134, pp. 1160-1166. [DOI: https://dx.doi.org/10.1542/peds.2014-0808]
7. Alsamri, M.T.; Alabdouli, A.; Iram, D.; Alkalbani, A.M.; Almarzooqi, A.S.; Souid, A.K.; Vijayan, R. A study on the genetics of primary ciliary dyskinesia. J. Clin. Med.; 2021; 10, 5102. [DOI: https://dx.doi.org/10.3390/jcm10215102]
8. Zhao, X.; Bian, C.; Liu, K.; Xu, W.; Liu, Y.; Tian, X.; Bai, J.; Xu, K.F.; Zhang, X. Clinical characteristics and genetic spectrum of 26 individuals of Chinese origin with primary ciliary dyskinesia. Orphanet J. Rare Dis.; 2021; 16, 293. [DOI: https://dx.doi.org/10.1186/s13023-021-01840-2] [PubMed: https://www.ncbi.nlm.nih.gov/pubmed/34210339]
9. De Jesús-Rojas, W.; Muñiz-Hernández, J.; Alvarado-Huerta, F.; Meléndez-Montañez, J.M.; Santos-López, A.J.; Mosquera, R.A. The Genetics of Primary Ciliary Dyskinesia in Puerto Rico. Diagnostics; 2022; 12, 1127. [DOI: https://dx.doi.org/10.3390/diagnostics12051127]
10. Hamamy, H. Consanguineous marriages preconception consultation in primary health care settings. J. Commun. Genet.; 2012; 3, pp. 185-192. [DOI: https://dx.doi.org/10.1007/s12687-011-0072-y]
11. Kuehni, C.E.; Frischer, T.; Strippoli, M.P.F.; Maurer, E.; Bush, A.; Nielsen, K.G.; Escribano, A.; Lucase, J.S.A.; Yiallouros, P.; Omran, H. et al. Factors influencing age at diagnosis of primary ciliary dyskinesia in European children. Eur. Respir. J.; 2010; 36, pp. 1248-1258. [DOI: https://dx.doi.org/10.1183/09031936.00001010]
12. Shapiro, A.J.; Davis, S.D.; Polineni, D.; Manion, M.; Rosenfeld, M.; Dell, S.D.; Chilvers, M.A.; Ferkol, T.W.; Zariwala, M.A.; Sagel, S.D. et al. Diagnosis of primary ciliary dyskinesia: An official American thoracic society clinical practice guideline. Am. J. Respir. Crit. Care Med.; 2018; 197, pp. e24-e39. [DOI: https://dx.doi.org/10.1164/rccm.201805-0819ST] [PubMed: https://www.ncbi.nlm.nih.gov/pubmed/29905515]
13. O’Connor, M.G.; Horani, A.; Shapiro, A.J. Progress in diagnosing primary ciliary dyskinesia: The north american perspective. Diagnostics; 2021; 11, 1278. [DOI: https://dx.doi.org/10.3390/diagnostics11071278]
14. Lucas, J.S.; Barbato, A.; Collins, S.A.; Goutaki, M.; Behan, L.; Caudri, D.; Dell, S.; Eber, E.; Escudier, E.; Hirst, R.A. et al. European Respiratory Society guidelines for the diagnosis of primary ciliary dyskinesia. Eur. Respir. J.; 2017; 49, 1601090. [DOI: https://dx.doi.org/10.1183/13993003.01090-2016] [PubMed: https://www.ncbi.nlm.nih.gov/pubmed/27836958]
15. Wheway, G.; Thomas, N.S.; Carroll, M.; Coles, J.; Doherty, R.; Goggin, P.; Green, B.; Harris, A.; Hunt, D.; Jackson, C.L. et al. Whole genome sequencing in the diagnosis of primary ciliary dyskinesia. BMC Med. Genom.; 2021; 14, 234. [DOI: https://dx.doi.org/10.1186/s12920-021-01084-w] [PubMed: https://www.ncbi.nlm.nih.gov/pubmed/34556108]
16. Wallmeier, J.; Bracht, D.; Alsaif, H.S.; Dougherty, G.W.; Olbrich, H.; Cindric, S.; Dzietko, M.; Heyer, C.; Teig, N.; Thiels, C. et al. Mutations in TP73 cause impaired mucociliary clearance and lissencephaly. Am. J. Hum. Genet.; 2021; 108, pp. 1318-1329. [DOI: https://dx.doi.org/10.1016/j.ajhg.2021.05.002]
17. Alsaadi, M.M.; Erzurumluoglu, A.M.; Rodriguez, S.; Guthrie, P.A.I.; Gaunt, T.R.; Omar, H.Z.; Mubarak, M.; Alharbi, K.K.; Al-Rikabi, A.C.; Day, I.N.M. Nonsense mutation in coiled-coil domain containing 151 gene (CCDC151) causes primary ciliary dyskinesia. Hum. Mutat.; 2014; 35, pp. 1446-1448. [DOI: https://dx.doi.org/10.1002/humu.22698]
18. Behan, L.; Dimitrov, B.D.; Kuehni, C.E.; Hogg, C.; Carroll, M.; Evans, H.J.; Goutaki, M.; Harris, A.; Packham, S.; Walker, W.T. et al. PICADAR: A diagnostic predictive tool for primary ciliary dyskinesia. Eur. Respir. J.; 2016; 47, pp. 1103-1112. [DOI: https://dx.doi.org/10.1183/13993003.01551-2015]
19. Brietzke, S.E.; Shin, J.J.; Choi, S.; Lee, J.T.; Parikh, S.R.; Pena, M.; Prager, J.D.; Ramadan, H.; Veling, M.; Corrigan, M. et al. Clinical consensus statement: Pediatric chronic rhinosinusitis. Otolaryngol. Head Neck Surg.; 2014; 151, pp. 542-553. [DOI: https://dx.doi.org/10.1177/0194599814549302]
20. Al-Kouatly, H.B.; Makhamreh, M.M.; Rice, S.M.; Smith, K.; Harman, C.; Quinn, A.; Valcarcel, B.N.; Firman, B.; Liu, R.; Hegde, M. et al. High diagnosis rate for nonimmune hydrops fetalis with prenatal clinical exome from the Hydrops-Yielding Diagnostic Results of Prenatal Sequencing (HYDROPS) Study. Genet. Med.; 2021; 23, pp. 1325-1333. [DOI: https://dx.doi.org/10.1038/s41436-021-01121-0]
21. Asseri, A.A.; Alzoani, A.; Almazkary, A.M.; Abdulaziz, N.; Almazkary, M.H.; Alahmari, S.A.; Duraisamy, A.J.; Sureshkumar, S. Mucopolysaccharidosis Type I Presenting with Persistent Neonatal Respiratory Distress: A Case Report. Diseases; 2023; 11, 67. [DOI: https://dx.doi.org/10.3390/diseases11020067]
22. Omran, H.; Häffner, K.; Völkel, A.; Kuehr, J.; Ketelsen, U.-P.; Ross, U.-H.; Konietzko, N.; Wienker, T.; Brandis, M.; Hildebrandt, F. Homozygosity Mapping of a Gene Locus for Primary Ciliary Dyskinesia on Chromosome 5p and Identification of the Heavy Dynein Chain DNAH5 as a Candidate Gene. Am. J. Respir. Cell Mol. Biol.; 2000; 23, pp. 696-702. [DOI: https://dx.doi.org/10.1165/ajrcmb.23.5.4257] [PubMed: https://www.ncbi.nlm.nih.gov/pubmed/11062149]
23. Goutaki, M.; Pedersen, E.S.L. Phenotype-genotype associations in primary ciliary dyskinesia: Where do we stand?. Eur. Respir. J.; 2021; 58, 2. [DOI: https://dx.doi.org/10.1183/13993003.00392-2021] [PubMed: https://www.ncbi.nlm.nih.gov/pubmed/34353866]
24. Machogu, E.; Gaston, B. Respiratory distress in the newborn with primary ciliary dyskinesia. Children; 2021; 8, 153. [DOI: https://dx.doi.org/10.3390/children8020153]
25. Emiralioğlu, N.; Taşkıran, E.Z.; Koşukcu, C.; Bilgiç, E.; Atilla, P.; Kaya, B.; Günaydın, Ö.; Yüzbaşıoğlu, A.; Tuğcu, G.D.; Ademhan, D. et al. Genotype and phenotype evaluation of patients with primary ciliary dyskinesia: First results from Turkey. Pediatr. Pulmonol.; 2020; 55, pp. 383-393. [DOI: https://dx.doi.org/10.1002/ppul.24583]
26. Hammoudeh, S.; Gadelhak, W.; Janahi, I.A. Primary ciliary dyskinesia among Arabs: Where do we go from here?. Paediatr. Respir. Rev.; 2019; 29, pp. 19-22. [DOI: https://dx.doi.org/10.1016/j.prrv.2018.09.002]
27. Stillwell, P.C.; Wartchow, E.P.; Sagel, S.D. Primary ciliary dyskinesia in children: A review for pediatricians, allergists, and pediatric pulmonologists. Pediatr. Allergy Immunol. Pulmonol.; 2011; 24, pp. 191-196. [DOI: https://dx.doi.org/10.1089/ped.2011.0099] [PubMed: https://www.ncbi.nlm.nih.gov/pubmed/22276227]
28. Coren, M.E.; Meeks, M.; Morrison, I.; Buchdahl, R.M.; Bush, A. Primary ciliary dyskinesia: Age at diagnosis and symptom history. Acta Paediatr.; 2002; 91, pp. 667-669. [DOI: https://dx.doi.org/10.1111/j.1651-2227.2002.tb03299.x]
29. Goutaki, M.; Papon, J.F.; Boon, M.; Casaulta, C.; Eber, E.; Escudier, E.; Halbeisen, F.S.; Harris, A.; Hogg, C.; Honore, I. et al. Standardised clinical data from patients with primary ciliary dyskinesia: FOLLOW-PCD. ERJ Open Res.; 2020; 6, [DOI: https://dx.doi.org/10.1183/23120541.00237-2019]
30. Wang, R.; Yang, D.; Guo, T.; Lei, C.; Chen, X.; Kang, X.; Qing, J.; Luo, H. Case Report: Identification of a Novel ODAD3 Variant in a Patient with Primary Ciliary Dyskinesia. Front. Genet.; 2021; 12, 652381. [DOI: https://dx.doi.org/10.3389/fgene.2021.652381]
31. Alzaid, M.; Al-Mobaireek, K.; Almannai, M.; Mukhtar, G.; Eltahir, S.; Zafar, A.; Zada, A.P.; Alotaibi, W. Clinical and molecular characteristics of primary ciliary dyskinesia: A tertiary care centre experience. Int. J. Pediatr. Adolesc. Med.; 2021; 8, pp. 258-263. [DOI: https://dx.doi.org/10.1016/j.ijpam.2021.03.002] [PubMed: https://www.ncbi.nlm.nih.gov/pubmed/34401452]
32. Al-Owain, M.; Al-Zaidan, H.; Al-Hassnan, Z. Map of autosomal recessive genetic disorders in Saudi Arabia: Concepts and future directions. Am. J. Med. Genet. A; 2012; 158A, pp. 2629-2640. [DOI: https://dx.doi.org/10.1002/ajmg.a.35551]
33. Mabrouk, I.; Al-Harthi, N.; Mani, R.; Montantin, G.; Tissier, S.; Lagha, R.; Ben Abdallah, F.; Hassan, M.M.; Alhomrani, M.; Gaber, A. Combining RSPH9 founder mutation screening and next-generation sequencing analysis is efficient for primary ciliary dyskinesia diagnosis in Saudi patients. J. Hum. Genet.; 2022; 67, pp. 381-386. [DOI: https://dx.doi.org/10.1038/s10038-021-01006-9]
34. Mani, R.; Belkacem, S.; Soua, Z.; Chantot, S.; Montantin, G.; Tissier, S.; Copin, B.; Bouguila, J.; Rive Le Gouard, N.; Boughamoura, L. et al. Primary ciliary dyskinesia gene contribution in Tunisia: Identification of a major Mediterranean allele. Hum. Mutat.; 2020; 41, pp. 115-121. [DOI: https://dx.doi.org/10.1002/humu.23905] [PubMed: https://www.ncbi.nlm.nih.gov/pubmed/31469207]
35. Fassad, M.R.; Shoman, W.I.; Morsy, H.; Patel, M.P.; Radwan, N.; Jenkins, L.; Cullup, T.; Fouda, E.; Mitchison, H.M.; Fasseeh, N. Clinical and genetic spectrum in 33 Egyptian families with suspected primary ciliary dyskinesia. Clin. Genet.; 2020; 97, pp. 509-515. [DOI: https://dx.doi.org/10.1111/cge.13661]
36. Pereira, R.; Barbosa, T.; Cardoso, A.L.; Sá, R.; Sousa, M. Cystic fibrosis and primary ciliary dyskinesia: Similarities and differences. Respir. Med.; 2023; 209, 107169. [DOI: https://dx.doi.org/10.1016/j.rmed.2023.107169] [PubMed: https://www.ncbi.nlm.nih.gov/pubmed/36828173]
37. Cohen-Cymberknoh, M.; Simanovsky, N.; Hiller, N.; Gileles Hillel, A.; Shoseyov, D.; Kerem, E. Differences in disease expression between primary ciliary dyskinesia and cystic fibrosis with and without pancreatic insufficiency. Chest; 2014; 145, pp. 738-744. [DOI: https://dx.doi.org/10.1378/chest.13-1162]
38. Brody, A.S.; Kosorok, M.R.; Li, Z.; Broderick, L.S.; Foster, J.L.; Laxova, A.; Bandla, H.; Farrellj, P.M. Reproducibility of a Scoring System for Computed Tomography Scanning in Cystic Fibrosis. J. Thorac. Imag.; 2006; 21, pp. 14-21. [DOI: https://dx.doi.org/10.1097/01.rti.0000203937.82276.ce]
39. Goutaki, M.; Halbeisen, F.S.; Barbato, A.; Crowley, S.; Harris, A.; Hirst, R.A.; Karadag, B.; Martinu, V.; Morgan, L.; O’callaghan, C. et al. Late diagnosis of infants with PCD and neonatal respiratory distress. J. Clin. Med.; 2020; 9, 2871. [DOI: https://dx.doi.org/10.3390/jcm9092871]
You have requested "on-the-fly" machine translation of selected content from our databases. This functionality is provided solely for your convenience and is in no way intended to replace human translation. Show full disclaimer
Neither ProQuest nor its licensors make any representations or warranties with respect to the translations. The translations are automatically generated "AS IS" and "AS AVAILABLE" and are not retained in our systems. PROQUEST AND ITS LICENSORS SPECIFICALLY DISCLAIM ANY AND ALL EXPRESS OR IMPLIED WARRANTIES, INCLUDING WITHOUT LIMITATION, ANY WARRANTIES FOR AVAILABILITY, ACCURACY, TIMELINESS, COMPLETENESS, NON-INFRINGMENT, MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE. Your use of the translations is subject to all use restrictions contained in your Electronic Products License Agreement and by using the translation functionality you agree to forgo any and all claims against ProQuest or its licensors for your use of the translation functionality and any output derived there from. Hide full disclaimer
© 2023 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (https://creativecommons.org/licenses/by/4.0/). Notwithstanding the ProQuest Terms and Conditions, you may use this content in accordance with the terms of the License.
Abstract
Background: Primary ciliary dyskinesia (PCD, MIM 244400) is an inherited ciliopathy disorder characterized by recurrent sinopulmonary infections, subfertility, and laterality defects. The true incidence of PCD in Saudi Arabia is not known, but it is likely underdiagnosed due to the high prevalence of consanguineous marriages. In this study, we aim to study the clinical and genetic characteristics of PCD patients in the southwestern region of Saudi Arabia to provide guidance to clinicians and researchers studying PCD. Methods: This was a cross-sectional study conducted between 2019 and 2023 in Abha Maternity and Children’s Hospital. Twenty-eight patients with clinically diagnosed PCD were recruited. The diagnosis of PCD was confirmed via whole-exome sequencing. Results: A total of 28 patients from 20 families were identified and recruited for this study. The median age of patients was 7.5 years (IQR = 3, 13 years). The people of different sexes were evenly distributed, and 18 patients (64%) had neonatal respiratory distress (NRD). The median age of diagnosis was 5.5 years (IQR = 2, 11 years), while the age when the first symptoms appeared was 3 months old (IQR = 1, 6 months). The prevalence of a chronic wet cough, chronic rhinosinusitis, ear infections were 100% (n = 28), 78.6% (n = 22), and 67.9% (19), respectively. The most common gene in our study was DNAH5, which represented 17.9% (five out of twenty-eight) of the cases. Furthermore, the remaining pathogenic variants included: 14.3% with RSPH9 in four individuals (three families), 14.3% with DNAI2 in four individuals (two families), and 10.7% with LRRC56 in three individuals (one family). The most common findings on the chest CT scans were consolidation (seen in all patients), mucus plugging (seen in 95%), and bronchiectasis (seen in 77%). In the patients with bronchiectasis, the most commonly affected lobes were the right lower lobe (88%) and left lower lobe (76%). The patients with PCD and situs inversus were more likely to experience NRD than the patients with PCD and situs solitus. The median PICADAR score in the patients with PCD and situs inversus (median: 11.5; Q1: 10–Q3: 12.5) was significantly higher compared to those with PCD and situs solitus (median: 7.5; Q1: 5.8–Q3: 8) (U = 10.5; p < 0.001). Conclusion: This study provides preliminary data on the clinical and genetic characteristics of PCD patients in the southwestern region of Saudi Arabia. We found that DNAH5 and RSPH9 genes were the most common genes among the studied population. Furthermore, PCD should be considered for each child with early NRD and laterality defects, and further confirmatory tests are recommended. These findings also highlight the need for greater awareness of the disease in daily clinical practice to facilitate early diagnosis and avoid irreversible lung damage.
You have requested "on-the-fly" machine translation of selected content from our databases. This functionality is provided solely for your convenience and is in no way intended to replace human translation. Show full disclaimer
Neither ProQuest nor its licensors make any representations or warranties with respect to the translations. The translations are automatically generated "AS IS" and "AS AVAILABLE" and are not retained in our systems. PROQUEST AND ITS LICENSORS SPECIFICALLY DISCLAIM ANY AND ALL EXPRESS OR IMPLIED WARRANTIES, INCLUDING WITHOUT LIMITATION, ANY WARRANTIES FOR AVAILABILITY, ACCURACY, TIMELINESS, COMPLETENESS, NON-INFRINGMENT, MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE. Your use of the translations is subject to all use restrictions contained in your Electronic Products License Agreement and by using the translation functionality you agree to forgo any and all claims against ProQuest or its licensors for your use of the translation functionality and any output derived there from. Hide full disclaimer
Details


1 Department of Child Health, College of Medicine, King Khalid University, Abha 62529, Saudi Arabia;
2 Departments of Pediatrics, King Khalid University Medical City, Abha 62223, Saudi Arabia;
3 College of Medicine, King Khalid University, Abha 62529, Saudi Arabia;
4 Department of Pediatrics, Khamis Mushayt Children Hospital, Khamis Mushayt 62454, Saudi Arabia;
5 Department of Pulmonology, Aseer Central Hospital, Abha 62523, Saudi Arabia;
6 Department of Pediatrics, King Fahad Military Hospital, Khamis Mushayt 31932, Saudi Arabia;
7 Department of Pediatrics, Abha Maternity & Children Hospital, Abha 3613, Saudi Arabia;