Chin Yuet Meng, Puteri J Noor, Azli Ismail, Mohd Fadly MA and Zubaidah Zakaria (2014).Chromosomal breakage test in the diagnosis of fanconi anema in patients with aplastic anemia. Current Research in Medicine and Medical Sciences 4(1): 3-6
Fanconi anemia (FA) is a rare recessive genetic disorder characterized by bone marrow failure, developmental delay, congenital malformations, genomic instability and a high cancer risk. To date 15 different FA genes have been identified. Chromosomal breakage test (CBT) using mitomycin C in peripheral blood lymphocyte culture to diagnose FA is performed as a routine diagnostic test by our Cytogenetic Laboratory. We report here the findings of CBT on the blood samples of 82 patients with aplastic anemia (AA). Three out of 82 AA patients (3.7%) were positive for CBT. The diagnosis of FA was made only when CBT was positive, and the results consistent with clinical and hematological data. About 96.3% of the AA patients were negative for CBT. Genetic reversion in FA may result in ‘spontaneous’ hematologic improvement and lymphocyte mosaicism, thus giving a false negative result for CBT. In patients who were negative for chromosomal breakage blood test and if FA is highly suspected, then the next tier of tests should be considered. FA testing could be performed on skin fibroblasts to overcome misleading results in blood lymphocytes.