Growth and lung function in Asian patients with cystic fibrosis

A Case Report of the First Filipino Infant Diagnosed with Cystic Fibrosis through the Philippine Newborn Screening Program

Cystic Fibrosis (CF) is a rare condition among Asians and has not been reported in the Philippines as of this time. The inclusion of this disease in the Philippines' Expanded Newborn Screening Program (ENBS) has provided this Filipino family the opportunity of early detection and appropriate management of this condition that could ensure the survival of the proband and his other surviving siblings. Here we present a case of a 24-month-old male who had a positive Expanded Newborn Screening (ENBS) test for cystic fibrosis and eventually underwent further tests to confirm a homozygous deletion of exons 1 - 2 of the CFTR gene. He subsequently had recurrent pneumonia but is being managed by a team consisting of a pulmonologist, gastroenterologist, and a metabolic dietitian. The proband had an older sibling whose Newborn Screening (NBS) test was normal and who eventually expired from recurrent bouts of pneumonia. This sibling was never managed as a case of cystic fibrosis. Implications on the diagnosis and management of CF in the local setting is also discussed. The importance of an appropriate CF panel customized to the local population should be reiterated and carrier testing should be encouraged to help with proper family counseling for future pregnancies for the family involved.

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.

Gender Differences in Clinical Presentations of Cystic Fibrosis Patients in Azeri Turkish Population

BACKGROUND

Cystic fibrosis (CF) is an autosomal recessive disorder with several clinical presentations. This study was undertaken in the Azeri Turkish population in Iran, to investigate gender differences in the age at onset and diagnosis, age of death, and duration of illness of CF.

METHODS

The data of 331 CF patients from 2001 to 2015 was surveyed. Parameters including age, sex, ΔF508 mutation, age at onset, age at diagnosis, age of death and clinical presentations were evaluated for both sexes, using descriptive analysis. The association of gender with these variables was studied using logistic regression, chi-square test and Mann-Whitney U test by SPSS version 18. Odds ratio with a confidence interval of 95% and p≤0.05 was considered statistically significant.

RESULTS

The study included 191 males (57.7%) and 140 females (42.3%), all showing statistically significant difference (p<0.001). Age duration differed between genders. Male and female patients were further under 9 and 4 years, respectively. The occurrence of ΔF508 mutation was 0.51 times more in females than in males. Age, diagnosis and sex were closely associated: males were diagnosed at a significantly later age than females (p=0.05). While this compression performed based on clinical presentations, males with respiratory disease had a later median age at diagnosis than females at lifespan (p=0.001). The risk of infertility in males was approximately two times greater than in females (p=0.02).

CONCLUSION

These findings indicate gender differences in CF patients. Future studies are needed to establish other differences and evaluate the causes for the gender variations.

Association Between Outcomes and Demographic Factors in an Azeri Turkish Population With Cystic Fibrosis: A Cross-Sectional Study in Iran From 2001 Through 2014

Background

Outcomesforcystic fibrosis patients are improving rapidly. The demographic factors are notable variables inoutcomes, which can be evaluated and modified.

Objectives

This study was designed to investigate the association between outcome and demographic factors in patients with cystic fibrosis.

Patients and Methods

This was a cross-sectional study and data were gathered for 331 patients using the census method, from March 2001 to September 2014 in Iran. Data was analyzed using logistic regression analysis, chi-square test, and independent sample t test using SPSS 18. Odds ratio with confidence intervals of 95% and P < 0.05 were considered significant.

Results

There were 85 (25.7%) deceased patients and 246 (74.3%) living patients at the time of the study. Of the 246 living CF patients, 202 (82.2%) were less than nine years of age, and 77 (90.6%) out of the 85 deceased CF patients had died younger than four years of age. There was a significant difference between outcome and location of residence. The risk of mortality was 50% less in urban patients than in rural patients (P = 0.03). The risk of mortality was approximately two times higher in patients with a positive family history than in those with a negative family history (P = 0.02). The proportion of mortality was approximately two times, or 94%, higher for those in a consanguineous marriage than for those in a non-consanguineous marriage (P = 0.01).

Conclusions

The results demonstrated that the mortality rate was higher in CF patients with a positive family history, a consanguineous marriage, and residence in a rural area. Therefore, demographic factors play an important role in the outcome of cystic fibrosis. Unfortunately, these parameters, which can be managed easily and with low cost, have been overlooked.

Epidemiology and genetics of cystic fibrosis in Asia: In preparation for the next-generation treatments

Cystic fibrosis (CF) in the Asian population is less frequently reported due to under-diagnosis and lack of centralized CF patient registries. Clinical studies on CF cases from Asia have documented a severe course of the disease. The spectrum of the cystic fibrosis transmembrane conductance regulator (CFTR) variants in this population is quite heterogeneous. In total, 166 variants have been reported on approximately 3700 Asian CF chromosomes. The frequency of F508del among Asians is low compared with Caucasians. Recent in vitro studies have shown promise of small molecule correction and potentiation of 45 different CFTR variants. Of these variants, 16 (including G551D and F508del) have also been observed among Asian CF individuals. We suggest undertaking molecular studies extensively to annotate CFTR variants that will help Asian CF individuals to benefit from the precision medicine gaining momentum in the Western countries.

Clinical and mutation profile of children with cystic fibrosis in Jammu and Kashmir

OBJECTIVE

To study the clinical and mutation profiles of children with cystic fibrosis in Jammu and Kashmir.

METHODS

One hundred consecutive patients presenting with one or more phenotypic features suggestive of cystic fibrosis (CF) were screened by quantitative sweat chloride testing. For patients with positive/equivocal test result on two occasions, CFTR gene mutation analysis was done by polymerase chain reaction.

RESULTS

Of the 100 patients, 18 (10 females) were diagnosed to have CF at a median age of 10.5 y (IQR 4.75-15.25 y) while the median age at the onset of symptoms was 12 mo (IQR 4-63 mo) with a delay in diagnosis by 102.4±80.5 months. Clinical features at presentation included failure to thrive (94.4%), chronic cough (78%), recurrent pneumonia (61%), persistent pneumonia (11%), and chronic diarrhea (50%). Positive sweat chloride (>60 meq/L) was seen in 14 (14%) patients and 4 (4%) patients had equivocal (40-60 meq/L) value on two different occasions. Mutational analysis done in 15 patients showed DeltaF508 mutation in 20% (3/15) patients in homozygous form and in 13% (2/15) patients in heterozygous form. Intron 19 mutation 3849+10kb C>T was found in 40% (6/15) in heterozygous form. One (6.6%) patient had DeltaF508 and 3849+10kbC>T mutations in compound heterozygous form. Patients with equivocal sweat chloride and 3849+10kbC>T mutation had delayed onset of pulmonary involvement.

CONCLUSION

3849 +10kbC>T mutation appears to be common in children with cystic fibrosis in Jammu and Kashmir followed by DeltaF508, although the data are quite limited. Although presentation is delayed and sweat chloride is in the equivocal range, severe lung involvement may occur in these patients.

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.

Factors effecting impact of Aspergillus fumigatus sensitization in cystic fibrosis

The clinical impact of Aspergillus fumigatus (Af) sensitization in cystic fibrosis (CF) is controversial. We examined the effect of Af sensitization (Afs) on pulmonary function and growth using a retrospective cohort analysis over two 5-year study periods: 1996-2000 (19 Afs cases and 19 controls) and 2001-2005 (24 Afs cases and 23 controls). Sensitization was defined as Af specific radioallergosorbent test (RAST) >or= 17.5 iu/ml and total serum IgE level >or=150 iu/ml. We examined the impact of changing treatment schedules over these periods. Afs cases had lower median FEV(1) %predicted (%PR) compared to matched controls 1996: 67 versus 80, P < 0.01; 2001: 78 versus 93, P < 0.01. Afs cases in the 2001 cohort had a higher FEV(1) %PR compared to Afs cases in the 1996 cohort: 78 versus 67, P < 0.01. For the 1996 Afs cohort FEV(1) %PR fell significantly over 5 years but not for the 2001 Afs cohort. Af RAST and total IgE reflected the changes in pulmonary function. Children in the 2001 Afs cohort were prescribed significantly more oral antifungal treatment (odds ratio 4.3, 95%CI 1.2-15.7, P = 0.03). Afs children continue to have poorer lung function compared to controls but this observational, hypothesis generating study, suggests that the use of antifungal treatment is associated with better lung function.