Microarray, gene sequencing, and reverse transcriptase–polymerase chain reaction analyses of a cryptic PML-RARA translocation

Single-Nucleotide Polymorphism Array-Based Karyotyping of Acute Promyelocytic Leukemia

“…Cases with duplication of the PML gene were recurrent, and also similar cases have been reported before [18]. It is interesting that some of these cases had a cryptic t(15;17) according to conventional cytogenetics.…”

“…APL cases with cryptic t(15;17) may be due to small interstitial insertions of PML or RARA genes one beside the other [19] or even ectopic to the natural gene loci. [18], [20], [21] Small deletions very close to the translocated genes have been reported in 10-30% of patients with CBF-AML [t(8;21) and inv(16)] and CML [t(9;22)], usually involving the translocated genes [10], [14]. Less frequently (∼1%), some cases have been described in such leukemias with deletions located in more telomeric or centromeric regions from the translocated gene, [10], [14] resembling our case APL_20.…”

Value of Oligonucleotide-Based Array Comparative Genomic Hybridization for Diagnosis of Acute Promyelocytic Leukemia in a Patient Negative for t(15;17)(q24.1;q21.2)/Promyelocytic Leukemia-Retinoic Acid Receptor, Alpha by Conventional Cytogenetics and Fluorescence In Situ Hybridization

“…Though DNA sequencing has been shown to reveal cryptic PML/RARA rearrangements at the DNA level, the procedure remains expensive, takes significant time, and is dependent on extensive data analysis and DNA read depth to reveal such events. 16 Alternatively, the more affordable and rapid traditional microarray assessment has been used to show the presence of a small copy gain within a PML gene inserted elsewhere in the genome in an RT-PCR positive case of APL, 17 suggestive of a cryptic insertion event. However, detection of such a cryptic copy gain does not provide evidence of a genomic fusion event.…”

“…Koshy et al reported an APL case presented with negative karyotyping and FISH analysis but positive in RT-PCR and single nucleotide polymorphism microarray for intragenic PML gene duplication. 17 Use of a dual color dual fusion PML-RARA FISH probe identified a small extra signal of PML which appears to be located in either chromosome 19 or 20. However, RARA insert could not be detected using either RARA FISH probe or the array.…”

Dual-probe electrochemical DNA biosensor based on the “Y” junction structure and restriction endonuclease assisted cyclic enzymatic amplification for detection of double-strand DNA of PML/RARα related fusion gene

“…Thus, the detection of PML/RARα fusion gene is significant in early diagnosis, monitoring of minimal residual disease and prognosis about APL. Currently, the monitoring and testing methods of clinical diagnosis and prognosis about fusion gene of APL have mainly included flow cytometry (FCM) (Wolfgang et al, 2010), fluorescence in situ hybridization (FISH) (Choughule et al, 2009), chromosome analysis (Tirado et al, 2003) and real-time quantitative reverse transcription PCR techniques (RT-PCR) (Koshy et al, 2012). But there are some limitations in these methods, such as low sensitivity, poor precision, timeconsuming and expensiveness.…”