Genotype–Phenotype Correlation in Children With Cystic Fibrosis From India: A Multicentric Study

The study aimed to report genotype-phenotype correlation in children with cystic fibrosis. This prospective multicentric study was done at four centres. Variants were tested for two common variants, followed by exome sequencing using NGS. Patients with cystic fibrosis who have one or more pathogenic/likely pathogenic variants were included in this study. The study included 260 children. Boys were more common (70.6% vs. 55.3%), and consanguinity was more prevalent (31.7% vs. 14.2%) in patients with non-c.1520_1522del variants. The 3849+10kbC>T variant had less pancreatic insufficiency, a higher age at diagnosis, and lower sweat chloride values compared to the c.1520_1522del variant. The median (IQR) age at diagnosis was significantly lower [1.5 (0.5, 7) vs. 4 (1.1, 9.4 years)], and pancreatic insufficiency (80.4% vs. 66.4%) and consanguinity (44% vs. 7.1%) were significantly more frequent in patients with homozygous variants compared to compound heterozygous variants. There was no difference in the proportion of Pseudomonas or Staphylococcus colonisation, spirometry parameters or frequency of bronchiectasis amongst various genetic groups. To conclude, the proportion of boys and consanguinity was higher with non-c.1520_1522del variants. The 3849+10kbC>T variant exhibited some peculiar phenotypic features. The patients with homozygous variants were younger at diagnosis and had higher pancreatic insufficiency.