Cystic fibrosis with homozygous R553X mutation in a Taiwanese child

Genetic analysis and functional study of novel CFTR variants in Chinese children with cystic fibrosis

OBJECTIVES

To describe the clinical characteristics of Chinese cystic fibrosis (CF) patients and to investigate the variants of CFTR and their potential pathogenicity.

STUDY DESIGN

Chinese patients with potential CF diagnosis were studied. Clinical data were reviewed retrospectively from medical records. Whole exome sequencing and genetic evaluation were conducted to explore potential gene variants. The disruption of the variants to protein structure and function was explored and validated using in vitro experiments and in silico analysis.

RESULTS

Four patients were recruited to the study, three of them were diagnosed as CF, and one was diagnosed as CFTR-related disorder. The age at symptom onset for the patients in this study ranged from newborn to 6 years, while the age at diagnosis varied from 3 to 11 years. All four patients exhibited bilateral diffuse bronchiectasis with Pseudomonas aeruginosa infections, and three of them had malnutrition. Finger clubbing was observed in three patients, two of whom displayed mixed ventilatory dysfunction. The CFTR variants spectrum of Chinese children with CF differs from that of Caucasian. A total of six variants were identified, two of which were first reported (c.1219G > T [p.Glu407*] and c.1367delT [p.Ala457Leufs*12]). The nonsense variants c.1219G > T, c.1657C > T and c.2551C > T and the frameshift variant c.1367delT were predicted to introduce premature stop codon and produce shorten CFTR protein, which was also first validated by in vitro truncation assay in this study. The missense variant c.1810A > C was predicted to disrupt the function of the nucleotide-binding domain 1 (NBD1) in the CFTR protein. The splicing variant c.1766 + 5G > T caused skipping of exon 13 and damaged the integrity of CFTR protein.

CONCLUSIONS

Our study expands the spectrum of phenotypes and genotypes for CF of Chinese origin, which differs significantly from that of Caucasian. Genetic analysis and counseling are crucial and deserve extensive popularization for the diagnosis ofCF in patients of Chinese origin.

[Cystic fibrosis primarily presenting with pseudo-Bartter syndrome: a report of three cases and literature review]

OBJECTIVES

To summarize the clinical characteristics and genetic variations in children with cystic fibrosis (CF) primarily presenting with pseudo-Bartter syndrome (CF-PBS), with the aim to enhance understanding of this disorder.

METHODS

A retrospective analysis was performed on the clinical data of three children who were diagnosed with CF-PBS in Hunan Children's Hospital from January 2018 to August 2023, and a literature review was performed.

RESULTS

All three children had the onset of the disease in infancy. Tests after admission showed hyponatremia, hypokalemia, hypochloremia, and metabolic alkalosis, and genetic testing showed the presence of compound heterozygous mutation in the CFTR gene. All three children were diagnosed with CF. Literature review obtained 33 Chinese children with CF-PBS, with an age of onset of 1-36 months and an age of diagnosis of 3-144 months. Among these children, there were 29 children with recurrent respiratory infection or persistent pneumonia (88%), 26 with malnutrition (79%), 23 with developmental retardation (70%), and 18 with pancreatitis or extrapancreatic insufficiency (55%). Genetic testing showed that c.2909G>A was the most common mutation site of the CFTR gene, with a frequency of allelic variation of 23% (15/66).

CONCLUSIONS

CF may have no typical respiratory symptoms in the early stage. The possibility of CF-PBS should be considered for infants with recurrent hyponatremia, hypokalemia, hypochloremia, and metabolic alkalosis, especially those with malnutrition and developmental retardation. CFTR genetic testing should be performed as soon as possible to help with the diagnosis of CF.

The incidence of bronchiectasis in chronic obstructive pulmonary disease

Bronchiectasis is a common comorbidity in chronic obstructive pulmonary disease (COPD). There are limited data regarding the incidence of bronchiectasis in COPD. The purpose of the study was to use a nationwide database to evaluate the incidence of bronchiectasis in COPD in Taiwan. We used a cohort of 2,000,000 individuals followed from 2005 to 2018. Patients with COPD diagnosed between January 1, 2011, and December 31, 2017, were selected, and those with bronchiectasis before COPD were excluded. In total, 134,366 patients with COPD were enrolled, and propensity score matching was used to ensure homogeneity of baseline characteristics between the COPD and non-COPD groups. The incidence rate of bronchiectasis was higher in the COPD group than in the non-COPD group (87.83 vs 69.80 per 10,000 person-years). The adjusted hazard ratio (1.9; 95% confidence interval 1.75-2.05; P < 0.001) of bronchiectasis indicated that the risk of bronchiectasis was 1.9 times higher for patients with COPD than for patients without COPD. In the COPD group, the age-stratified incidence rates of bronchiectasis increased with age (55.01, 80.92, 101.52, and 105.23 for 40-49, 50-59, 60-69, and over 70 years, respectively). The incidence of bronchiectasis was higher in patients with COPD than in the general population, the risk of bronchiectasis increased with age in COPD, and post-tuberculosis status was an important risk factor for bronchiectasis.

Genetic spectrum of Chinese children with cystic fibrosis: comprehensive data analysis from the main referral centre in China

BACKGROUND AND OBJECTIVES

Cystic fibrosis (CF) is a heterogeneous disease with a diverse genetic spectrum among populations. Few patients with CF of Chinese origin have been reported worldwide. The objective of this study is to characterise the genotypic features of CF in Chinese children.

METHODS

We recruited and characterised the genetic manifestations of 103 Chinese children with CF in Beijing Children's Hospital from 2010 to 2022. Whole-exome sequencing were performed to define the genotypes. Meanwhile, other 99 genetically confirmed patients with Chinese origin described in 45 references were also summarised.

RESULTS

158 different variants including 23 novel observations were identified after sequencing. The majority of CFTR variants (82.3%) in Chinese have been observed only once or twice. 43.7% of the variants were only identified in patients of Chinese origin. The c.2909G>A(p.Gly970Asp), c.1766+5G>T and c.1657C>T(p.Arg553X) were the most frequent variants among Chinese patients, with allele frequency of 12.1%, 5.4% and 3.6%, respectively. The first two variants both showed significant Chinese ethnic tendency, while the latter one most likely came from Europeans for historical reasons. They also demonstrated significant differences in geographical distribution. c.1521_1523delCTT(p.F508del) was rarely observed in patients of pure Chinese origin, with an allele frequency of 1.8%. Two de novo variants (c.960dupA[p.Ser321IlefsX43] and c.2491-2A>G) and two deep-intronic variants (c.3718-2477C>T and c.3874-4522A>G) were identified, which were also quite rare among Chinese.

CONCLUSIONS

The genetic spectrum of CF in Chinese is unique and quite different from that observed in Caucasians. The geographical distributions of the most frequent variants were reported for the first time.

Comparison of Microbiological Characteristics and Genetic Diversity between Burkholderia cepacia Complex Isolates from Vascular Access and Other Clinical Infections

Burkholderia cepacia complex (BCC) is a group of closely related bacteria with widespread environmental distribution. BCC bacteria are opportunistic pathogens that cause nosocomial infections in patients, especially cystic fibrosis (CF). Multilocus sequence typing (MLST) is used nowadays to differentiate species within the BCC complex. This study collected 41 BCC isolates from vascular access infections (VAIs) and other clinical infections between 2014 and 2020. We preliminarily identified bacterial isolates using standard biochemical procedures and further conducted recA gene sequencing and MLST for species identification. We determined genetic diversity indices using bioinformatics software. We studied 14 isolates retrieved from patients with VAIs and observed that Burkholderia cepacia was the predominant bacterial species, and B. contaminans followed by B. cenocepacia were mainly retrieved from patients with other infections. According to MLST data, we identified that all B. contaminans isolates belonged to ST102, while a wide variety of sequence types (STs) were found in B. cenocepacia isolates. In summary, the high diversity and easy transmission of BCC increase BCC infections, which provides insights into their potential clinical effects in non-CF infections.

A systematic review of the clinical and genetic characteristics of Chinese patients with cystic fibrosis

OBJECTIVES

To investigate and summarize the clinical and genetic characteristics of Chinese cystic fibrosis (CF) patients to improve clinicians' understanding and decrease the rates of misdiagnosis and missed diagnoses in China.

METHODS

The EMBASE, Cochrane Library, PubMed and SinoMed databases were searched for studies involving Chinese CF patients from January 1975 to August 2019.

RESULTS

In total, 113 Chinese patients, including 53 males and 60 females, were reported. Nineteen patients had a family history of CF. The median age at diagnosis was 8.7 years. Among Chinese CF patients, 70.8% had bronchiectasis, 9.7% had a hemoptysis history, 33.6% had clubbed fingers, 17.7% had allergic bronchopulmonary aspergillosis, and 29.2% had chronic diarrhea; the incidence of malnutrition was 52.2%. Five patients had jaundice, 26 patients had hepatomegaly, and 9 patients had meconium ileus in the neonatal period, and the incidence of liver cirrhosis was 5.3%. The predominant organism in airways was Pseudomonas aeruginosa, followed by Staphylococcus aureus. Seventy-nine patients underwent the sweat test, and all of them were positive, with an average chloride ion level of 122.2 mmol/L. Eighty-eight Chinese CF patients underwent genetic testing, and 74 CF transmembrane conductance regulator (CFTR) gene mutations were reported. The most common gene mutation was c.2909G→A. One Phe508del gene mutation was observed.

CONCLUSION

The common clinical manifestations and CFTR gene mutations in Chinese CF patients are different from those in Caucasian patients. The age at CF diagnosis in China is relatively old, suggesting that the CF incidence in China may be seriously underestimated.

c.753_754delAG, a novel CFTR mutation found in a Chinese patient with cystic fibrosis: A case report and review of the literature

BACKGROUND

Cystic fibrosis (CF) is rare in Asian populations relative to the Caucasian population. In this paper, we report the cystic fibrosis transmembrane conductance regulator (CFTR) variation in a family of Chinese CF patients, and systematically review the previous literature.

CASE SUMMARY

Here we report a 30-month-old Chinese girl who was diagnosed with CF based on her history and symptoms such as recurrent productive cough, wheezing with repeated infection of Pseudomonas aeruginosa, and parasinusitis. Chest computed tomography (CT) scanning revealed obvious exudative lesions and bilateral bronchiectasis. Liver CT scanning revealed a low-density lesion in the left lobe of the liver. A diagnosis of CF was made based upon CFTR gene tests. The CFTR gene was sequenced using the blood samples of her and her parents and showed a heterozygous novel missense mutation of c.753_754delAG in exon 7. In addition, a heterozygous c.1240 C>T mutation was found in exon 10 of the CFTR. The mutation c.753_754delAG was verified to have been inherited from her mother, and the c.1240 C>T mutation was from her father who was diagnosed with congenital absence of vas deferens.

CONCLUSION

A novel mutation of CFTR, c.753_754delAG, was found in a Chinese CF child. c.2909G>A is the most common mutation among Chinese CF patients.

Liver Failure in a Chinese Cystic Fibrosis Child With Homozygous R553X Mutation

Cystic fibrosis (CF) is a relatively rare disease in Asians with various clinical characteristics, including CF-associated liver disease (CFLD), which is a common early non-pulmonary complication. This case report describes a Chinese CF patient harboring a homozygous nonsense mutation (c.1657C>T, p.R553X) who was failure to thrive and had intermittently diarrhea during the first year after birth. Liver function test of the patient showed the mildly and intermittently elevated alanine aminotransferase (ALT) levels ranging from 70 to 92 U/L and aspartate aminotransferase (AST) levels ranging from 80 to 90 U/L, which began at 8 months of age and lasted for 4 years without CF diagnosis. In addition, abdominal computed tomography (CT) revealed diffuse fatty infiltration of the liver at 4 years old and gradually developed hepatic cirrhosis. Subsequently, cirrhosis rapidly progressed with obvious splenomegaly and pancreatic insufficiency and the patient died of liver failure with coagulopathy by the age of 6 years old. Pediatricians should remain vigilant to avoid failure to diagnose CF, the occurrence of which may be underestimated, and pay greater attention to the patients with atypical clinical manifestations in Asian countries.

Clinical and genetic characteristics of cystic fibrosis in CHINESE patients: a systemic review of reported cases

Cystic fibrosis (CF) is a rare disease most commonly seen in Caucasians. Only a few Chinese CF patients have been described in literature, taking into account the large population of China. In this systematic review, we collected the clinical and genetic information of 71 Chinese CF patients based on all available data. Compared with Caucasians, Chinese CF patients often present atypical symptoms, mainly displaying symptoms of pulmonary infection with fewer digestive symptoms. An ethnicity-specific CFTR variant spectrum was also observed in CF patients of Chinese origin, with p.Gly970Asp as the most common mutation while p.Phe508del, the most common pathogenic mutation in CF patients of Caucasian origin, is rare, suggesting the necessity of a Chinese-specific CFTR variant screening panel. Besides, multiplex ligation-dependent probe amplification analysis should be routinely considered, especially for those with unidentified mutations. Potential under-diagnosis of CF in Chinese patients might be caused by a combination of atypical clinical features and genetic heterogeneity in Chinese CF patients, the inaccessibility of sweat and genetic testing facilities, and the one-child policy in China. With the approval of promising small molecule correctors and potentiators, molecular characterization of Chinese-specific CFTR mutations will help to realize more precise treatment for Chinese CF patients.

Clinical characterization and diagnosis of cystic fibrosis through exome sequencing in Chinese infants with Bartter-syndrome-like hypokalemia alkalosis

Cystic fibrosis (CF) is a fatal autosomal-recessive disease caused by mutations in the CF transmembrane conductance regulator (CFTR) gene. CF is characterized by recurrent pulmonary infection with obstructive pulmonary disease. CF is common in the Caucasian population but is rare in the Chinese population. The symptoms of early-stage CF are often untypical and may sometimes manifest as Bartter syndrome (BS)-like hypokalemic alkalosis. Therefore, the ability of doctors to differentiate CF from BS-like hypokalemic alkalosis in Chinese infants is a great challenge in the timely and accurate diagnosis of CF. In China, sporadic CF has not been diagnosed in children younger than three years of age to date. Three infants, who were initially admitted to our hospital over the period of June 2013 to September 2014 with BS-like hypokalemic alkalosis, were diagnosed with CF through exome sequencing and sweat chloride measurement. The compound heterozygous mutations of the CFTR gene were detected in two infants, and a homozygous missense mutation was found in one infant. Among the six identified mutations, two are novel point mutations (c.1526G > C and c.3062C > T) that are possibly pathogenic. The three infants are the youngest Chinese patients to have been diagnosed with sporadic CF at a very early stage. Follow-up examination showed that all of the cases remained symptom-free after early intervention, indicating the potential benefit of very early diagnosis and timely intervention in children with CF. Our results demonstrate the necessity of distinguishing CF from BS in Chinese infants with hypokalemic alkalosis and the significant diagnostic value of powerful exome sequencing for rare genetic diseases. Furthermore, our findings expand the CFTR mutation spectrum associated with CF.

Four case reports of Chinese cystic fibrosis patients and literature review

AIM

Cystic fibrosis (CF) is an extremely rare disease in Asians. Here, we report four Chinese children with CF and review the literature about Chinese CF patients.

METHODS

The cystic fibrosis transmembrane conductance regulator (CFTR) gene testing was performed on four suspected patients for CF screening. We also reviewed the literature about Chinese CF patients from 1970s. The clinical data of all these CF patients were summarized.

RESULTS

We diagnosed four CF patients who had mutations in the CFTR gene. We identified six different mutations in the four patients. The c.1766+5G>T, c.595C>T, c.2909G>A, and c.4056G>C had been reported already. The two splicing mutations of c.579+1_579+2insACAT and c.1117-1G>C were novel mutations. There have been 46 Chinese CF patients reported in literature from 1974 up to present (2016.12). The clinical manifestations of CF involved several systems. The most common symptom was recurrent pulmonary infections. Thirty-three different mutations were identified; c.1766 + 5G>T was the most common mutation among Chinese CF patients. Only one of these mutations (R553X) was in the Caucasian CF screening panel. The spectrum of CFTR mutations in Chinese was highly different from that of Caucasian.

CONCLUSIONS

There was a high risk of misdiagnosis or delayed diagnosis of CF even in suspected cases in China. It is necessary to educate Chinese clinicians about the signs, symptoms, and diagnosis of cystic fibrosis and promote the implementation of the sweat chloride test.

Clinical Phenotypes and Genotypic Spectrum of Cystic Fibrosis in Chinese Children

OBJECTIVES

To characterize the clinical phenotypes and genotypic spectrum of cystic fibrosis (CF) in Chinese children.

STUDY DESIGN

We recruited and characterized the phenotypes of 21 Chinese children with CF. All 27 exons and their flanking sequences of the CF transmembrane conductance regulator gene were amplified and sequenced to define the genotypes.

RESULTS

Bronchiectasis (95.2%) and sinusitis (76.2%) were the most common clinical presentations among our patients. By contrast, pancreatic insufficiency was rare (14.3%). The predominant organism found in the airways was Pseudomonas aeruginosa (66.7%). There were obvious reductions of forced expiratory volume in the first second (mean ± SD: 71.8% ± 17.2% predicted) and forced expiratory flows at 75% of exhaled vital capacity (33.7% ± 20.4% predicted) in children with CF. Overall, we identified 22 different mutations, including 12 missense, 5 nonsense, 2 frameshift, 1 in-frame insertion, 1 splice site, and 1 3'untranslated region mutation. Of these, 7 were novel observations (W216X[780G→A], 1092insA, Q359X, D567Y, 2623-126T→C, 3439delA and 4575+110C→G), and the most common types were L88X and I556V. One de novo mutation (1092insA) was also revealed. Except for N1303K and R334W, none of them were present in the common Caucasian CF transmembrane conductance regulator mutation-screening panels.

CONCLUSIONS

There was a 5.7-year delay between the first clinical presentation and the eventual CF diagnosis, suggesting that CF may be underdiagnosed in China. The clinical phenotypes and genotypic spectrum are different from that observed in Caucasians.

p.G970D is the most frequent CFTR mutation in Chinese patients with cystic fibrosis

Cystic fibrosis (CF), the most common life-threatening autosomal recessive disorder in Caucasians, is caused by mutations in CF transmembrane conductance regulator gene (CFTR). We and others previously identified CFTR mutations in 20 Chinese patients with CF. In this study, eight Chinese patients with a clinical diagnosis of suspected CF were newly collected and screened for CFTR mutations using a combination of conventional Sanger sequencing and multiplex ligation-dependent probe amplification (MLPA) analysis. The CFTR mutations observed in Chinese CF patients, both reported previously and identified in the present study, were also summarized. In the newly collected patients, we identified 10 different CFTR mutations, including p.F508del, the most common CF-causing mutation in Caucasians, and three novel mutations (p.V1212Afs*15; p.L666* and p.A969A). Most notably, the previously reported p.G970D mutation was found in six patients, making it the most frequent CFTR mutation identified in Chinese CF patients thus far. In conclusion, we detected p.F508del for the first time, identified additional novel CFTR mutations and recorded the most frequent CF-causing mutation in Chinese CF patients.

A new compound heterozygous CFTR mutation in a Chinese family with cystic fibrosis

INTRODUCTION

Cystic fibrosis (CF) is the most common autosomal recessive disease among Caucasians but is rarer in the Chinese population, because mutations in the cystic fibrosis transmembrane conductance regulator (CFTR) gene.

OBJECTIVES

To elucidate the causative role of a novel compound heterozygous mutation of CF.

MATERIALS AND METHODS

In this study, clinical samples were obtained from two siblings with recurrent airway infections, clubbed fingers, salt-sweat and failure to gain weight in a non-consanguineous Chinese family. Next-generation sequencing was performed on the 27 coding exons of CFTR in both children, with confirmation by Sanger sequencing.

RESULTS

Next-generation sequencing showed the same compound heterozygous CFTR mutation (c.865A>T p.Arg289X and c.3651_3652insAAAT p.Tyr1219X) in both children.

CONCLUSIONS

As this mutation is consistent with the clinical manifestations of CF and no other mutations were detected after scanning the gene sequence, we suggest that the CF phenotype is caused by compound heterozygosity for c.865A>T and c.3651_3652insAAAT. As c865A>T is not currently listed in the "Cystic Fibrosis Mutation Database", this information about CF in a Chinese population is of interest.

Characterization of gene mutations and phenotypes of cystic fibrosis in Chinese patients

BACKGROUND AND OBJECTIVE

Cystic fibrosis (CF) is a relatively common autosomal recessive disorder in Caucasians. CF is considered a very rare disease in Asians, and fewer than 30 Chinese CF patients are reported in the literature. We enrolled seven patients of Chinese Han origin diagnosed with CF at the Peking Union Medical College Hospital, to characterize gene mutations and phenotypes of CF in Chinese patients.

METHODS

We analysed the clinical presentation and screened the coding region of the CFTR gene for each patient.

RESULTS

Patients were 0-6 years old at onset of symptoms and were 10-28 years old at the time of diagnosis with CF. None of the seven patients had a family history of CF, and only one patient had parents who were consanguineous. Two patients had gastrointestinal symptoms but stool Sudan III results were normal. Four of the seven CF patients also had allergic bronchopulmonary aspergillosis. The concentration of chloride in patients' sweat ranged from 66 mmol/l to 154 mmol/l. In total, we identified 11 different mutations in seven CF patients, including one novel mutation (△E7-E11). Only one of these mutations (R553X) is present in the Caucasian CFTR common mutation-screening panel; and none of the 11 mutations are common in Caucasian CF patients.

CONCLUSIONS

CF in China is difficult to diagnose because of a combination of low awareness, atypical clinical symptoms, and a lack of sweat and genetic testing facilities in most hospitals. The mutations identified in Chinese CF patients are different from the common Caucasian gene mutations.

Cystic fibrosis: experience in one institution

Cystic fibrosis (CF) is one of the most common autosomal recessive inherited disorders among Caucasians. Comparatively, it is considered to be a rare disease among Asians. To date, only a few cases of Taiwanese CF have been published. We report four CF cases from three families. Case 1 was the first report of CF associated with a homozygosity for the CF transmembrane conductance regulator gene (CFTR gene) mutation 3849+10kb C->T in a Taiwanese patient. Cases 2 and 3 had heterozygous c. 1898+5 G->T and heterozygous p. I1023R (novel mutation) for the CFTR gene mutation. Case 4 was homozygous for the CFTR gene mutation R553X being reported in 2005 and complicated with cor pulmonale. These four patients had received 300 mg bid aerosolized tobramycin treatment every other month.

Phenotype and genotype of two Taiwanese cystic fibrosis siblings and a survey of delta F508 in East Asians

BACKGROUND

Cystic fibrosis (CF) is considered to be a rare disease in Asians. We report two cases of CF in a 5-year-old girl and her newborn brother. They are of mixed parentage: a Taiwanese mother and an Australian father.

METHODS

A comprehensive mutational analysis of the cystic fibrosis transmembrane conductance regulator (CFTR) gene was completed. Literature was reviewed for delta F508 in East Asians.

RESULTS

Two mutation sites were identified in the siblings. The carrier status of their parents and elder brother were also confirmed: heterozygous delta F508 mutation from the father; 13 TG repeats in the IVS8-5T from the mother. An update of delta F508 mutation reported in East Asian patients from various ethnicities is included; most of them were of mixed parentage.

CONCLUSION

These two cases are the first report of cystic fibrosis associated with a delta F508 mutation in a Taiwanese patient attributable to a mutation most commonly seen in Caucasians. We found that the delta F508 mutation is of western origin. Asian patients are seldom found with this mutation unless they are of mixed parentage. Our findings provide further evidence that different ethnicities have their own set of CFTR mutations.

Cystic fibrosis in India

Cystic fibrosis (CF) was considered to be non-existent in Indian subcontinent. Reports in last one decade have suggested that cystic fibrosis occurs in India but its precise magnitude is not known. Studies on migrant Indian population in United States and United Kingdom estimate frequency of CF as 1:10,000 to 1:40,000. The clinical features are similar to that reported in Caucasian population. CF in Indian children is usually diagnosed late and in advanced stage. Children are more malnourished and may have clinically evident deficiency of fat soluble vitamins. The frequency of clubbing, colonization with Pseudomonas, and laboratory evidence of pseudo-Bartter syndrome is relatively more at the time of diagnosis. Diagnostic facilities in form of sweat chloride estimation and genetic studies are not available readily. Mutation profile is different. The frequency of common mutation F508del in Indian children is between 19% and 34%. Other mutations are heterogeneous. Management of CF in India is difficult due to less number of trained manpower, limited availability, and high cost of pharmacologic agents. The determinants of early death include: severe malnutrition and colonization with Pseudomonas at the time of diagnosis, more than four episodes of lower respiratory infection per year and age of onset of symptoms before 2 months of age. To conclude, CF does occur in India; however, precise magnitude of problem is not known. There is need to create awareness amongst pediatricians, developing diagnostic facilities, and management protocols based on locally available resources.