Related Experiment Video
Updated: Aug 7, 2025
Detection and Monitoring of Tumor Associated Circulating DNA in Patient Biofluids
Published on: June 8, 2019
Comprehensive laboratory diagnosis of Fanconi anaemia: comparison of cellular and molecular analysis
Gaurav Joshi1,2, Nancy Beryl Janet Arthur1, Thenral S Geetha3
1Department of Haematology, Christian Medical College Vellore, Vellore, Tamil Nadu, India.
Background:
Fanconi anaemia (FA) is a rare inherited bone marrow failure disease caused by germline pathogenic variants in any of the 22 genes involved in the FA-DNA interstrand crosslink (ICL) repair pathway. Accurate laboratory investigations are required for FA diagnosis for the clinical management of the patients. We performed chromosome breakage analysis (CBA), FANCD2 ubiquitination (FANCD2-Ub) analysis and exome sequencing of 142 Indian patients with FA and evaluated the efficiencies of these methods in FA diagnosis.
Methods:
We performed CBA and FANCD2-Ub analysis in the blood cells and fibroblasts of patients with FA. Exome sequencing with improved bioinformatics to detect the single number variants and CNV was carried out for all the patients. Functional validation of the variants with unknown significance was done by lentiviral complementation assay.
Results:
Our study showed that FANCD2-Ub analysis and CBA on peripheral blood cells could diagnose 97% and 91.5% of FA cases, respectively. Exome sequencing identified the FA genotypes consisting of 45 novel variants in 95.7% of the patients with FA. FANCA (60.2%), FANCL (19.8%) and FANCG (11.7%) were the most frequently mutated genes in the Indian population. A FANCL founder mutation c.1092G>A; p.K364=was identified at a very high frequency (~19%) in our patients.
Conclusion:
We performed a comprehensive analysis of the cellular and molecular tests for the accurate diagnosis of FA. A new algorithm for rapid and cost-effective molecular diagnosis for~90% of FA cases has been established.
