A new insight into CFTR allele frequency in Brazil through next generation sequencing

• Published in: Pediatric pulmonology Vol. 52; no. 10; pp. 1300 - 1305
• Main Authors: Nunes, Luisa M., Ribeiro, Roberto, Niewiadonski, Vivian D.T., Sabino, Ester, Yamamoto, Guilherme L., Bertola, Débora R., Gaburo, Nelson, da Silva Filho, Luiz Vicente R.F.
• Format: Journal Article
• Language: English
• Published: United States Wiley Subscription Services, Inc 01-10-2017
• Subjects: Adolescent; Alleles; Brazil - epidemiology; Child; cystic fibrosis; Cystic Fibrosis - epidemiology; Cystic Fibrosis - genetics; Cystic Fibrosis Transmembrane Conductance Regulator - genetics; cystic fibrosis transmembrane regulator; Female; Gene Frequency; Genotype; High-Throughput Nucleotide Sequencing; Humans; Male; Mutation; next generation sequencing; Population genetics; cystic fibrosis transmembrane regulator; cystic fibrosis; next generation sequencing
• ISSN: 8755-6863; 1099-0496
• DOI: 10.1002/ppul.23774

Background
As of 2013, fewer than 20% of patients in the Brazilian CF Registry had two CFTR mutations identified. The aim of this study was to sequence the coding region of the CFTR in Brazilian CF patients and determine the frequency of mutations in this cohort.
Methods
Patients with CF and those with suspected atypical CF or CFTR‐related disorders were invited to enroll. Total DNA was extracted from blood samples, quantified, and purified. Library preparation was performed using Ion Xpress™ Plus gDNA and Amplicon Library preparation kits (Life Technologies), as well as sequencing using the Ion Torrent platform (Life Technologies).
Results
A total of 141 patients were enrolled, and 45 mutations were identified. Among 126 CF patients, we identified mutations in 97.2% of alleles. The three most common mutations were F508del, G542X, and 3120 + 1G‐>A. Five novel pathogenic mutations were also identified.
Conclusions
Next generation sequencing (NGS) allowed the identification of mutations in most CF alleles and confirmed allelic heterogeneity in our population.