Clinical and genetic profiles of paediatric patients with cystic fibrosis from Western India.

BACKGROUND

Cystic fibrosis (CF) is a genetic disorder caused by genetic variant in the cystic fibrosis transmembrane regulator (CFTR) gene that affects around 89,000 people worldwide. Loss of the CFTR chloride channel due to pathogenic variants in the CFTR gene causes obstruction in the exocrine pancreas gland and reduced lung function.

OBJECTIVE

To determine the genotype and phenotype of patients with CF from western India.

MATERIALS AND METHODS

This was a single-center retrospective cross-sectional study conducted in a tertiary care super speciality paediatric hospital of Mumbai, India, comprising patients aged 0 to 18 years visiting a paediatric pulmonology clinic with suspected or confirmed diagnosis of CF.

RESULTS

The mean (SD) age of onset of symptoms was 6.8 (10.2) months and the mean (SD) age at diagnosis was 32.5 (50.5) months. The two most common genetic variants found in our patients were c. 1521_1523delCTT (F508del) (n = 21) and c.1367T>C (V456A) (n = 10). There were nine novel genetic variants identified that have not been reported so far. The mean (SD) age of onset of symptoms was 6.8 (10.2) months and mean (SD) age at diagnosis was 32.5 (50.5) months. The most common presenting features were recurrent respiratory infections (83%), malabsorption (79%), and failure to thrive (79%). Sweat chloride testing was conducted to establish the CFTR gene dysfunction and was positive in 79% (46/58) of patients and intermediate in 15% (n = 9/58) of patients. The two most common genetic variants found in our group of patients were c. 1521_1523delCTT (F508del) (n = 21) and c.1367T>C (V456A) (n = 10). There were nine novel genetic variants identified that have not been reported so far.

CONCLUSION

This study adds to the knowledge of genetic diversity in the pathogenic CFTR gene variants causing CF and highlights the importance of sequencing the entire CFTR gene as regional variations in the gene have been documented in India.