A strategy for molecular diagnostics of Fanconi anemia in Brazilian patients. Issue 4 (9th May 2017)

• Record Type: Journal Article
• Authors: Pilonetto, Daniela V.; Pereira, Noemi F.; Bonfim, Carmem M. S.; Ribeiro, Lisandro L.; Bitencourt, Marco A.; Kerkhoven, Lianne; Floor, Karijn; Ameziane, Najim; Joenje, Hans; Gille, Johan J. P.; Pasquini, Ricardo
• Is Part Of: Molecular genetics & genomic medicine. Volume 5:Issue 4(2017)
• Page Start: 360
• Page End: 372
• Publication Date: 2017-05-09
• Subjects: FANCA -- FANCC -- FANCG -- Fanconi anemia -- genetic subtypes -- molecular diagnostics -- mutation screening; Medical genetics -- Periodicals; Genomics -- Periodicals; 616.042
• DOI: 10.1002/mgg3.293
• Languages: English
• ISSNs: 2324-9269

Abstract

Abstract: Background: Fanconi anemia (FA) is a predominantly autosomal recessive disease with wide genetic heterogeneity resulting from mutations in several DNA repair pathway genes. To date, 21 genetic subtypes have been identified. We aimed to identify the FA genetic subtypes in the Brazilian population and to develop a strategy for molecular diagnosis applicable to routine clinical use. Methods: We screened 255 patients from Hospital de Clínicas, Universidade Federal do Paraná for 11 common FA gene mutations. Further analysis by multiplex ligation‐dependent probe amplification (MLPA) for FANCA and Sanger sequencing of all coding exons of FANCA, ‐C, and – G was performed in cases who harbored a single gene mutation. Results: We identified biallelic mutations in 128/255 patients (50.2%): 89, 11, and 28 carried FANCA, FANCC, and FANCG mutations, respectively. Of these, 71 harbored homozygous mutations, whereas 57 had compound heterozygous mutations. In 4/57 heterozygous patients, both mutations were identified by the initial screening, in 51/57 additional analyses was required for classification, and in 2/57 the second mutation remained unidentified. We found 52 different mutations of which 22 were novel. Conclusion: The proposed method allowed genetic subtyping of 126/255 (49.4%) patients at a significantly reduced time and cost, which makes molecular diagnosis of FA Brazilian patients feasible. Abstract : This study aimed at identifying the Fanconi anemia genetic subtypes in the Brazilian population and to develop a strategy for molecular diagnosis applicable to routine clinical use. A total of 255 FA patients were initially screened for common mutations in FANCA, FANCC, and FANCG genes. MLPA was used to detect FANCA large deletions, and Sanger sequencing of these genes was utilized when the second mutation was not identified in the heterozygous patients. The inclusion of the initial screening in the proposed strategy allowed genetic subtyping of 126/255 (49.4%) patients at a significantly reduced time and cost, which makes molecular diagnosis of FA Brazilian patients feasible.