TY - JOUR
T1 - Pitfalls of using polymerase chain reaction–based assays for JAK2 and CALR exon 9 variant testing in myeloproliferative neoplasms Knowing when to go the extra mile!
AU - Krishnamurthy, Kritika
AU - Chai, Jiani
AU - Wang, Yanhua
AU - Naeem, Rizwan
AU - Goldstein, D. Yitzchak
N1 - Publisher Copyright:
© 2024 Oxford University Press. All rights reserved.
PY - 2024/2/1
Y1 - 2024/2/1
N2 - Objectives: The BCR::ABL1 negative myeloproliferative neoplasms are sequentially tested for JAK2 p.V617F, followed by CALR exon 9 pathogenic variants. Historically, these variants were thought to be mutually exclusive. However, recent reports indicate coexisting JAK2 p.V617F and CALR exon 9 somatic variants. Methods: Analysis of JAK2 p.V617F and CALR exon 9 variant was performed by polymerase chain reaction (PCR)–based assays. Subsequent testing was performed on the Genexus integrated sequencer (ThermoFisher) using the Oncomine myeloid assay GX v2. Results: CALR exon 9 variants were positive in 3 cases, while 2 were positive for JAK2 p.V617F on PCR-based assays. Next-generation sequencing confirmed the JAK2 P.V617F status in all cases. CALR variants resulting in in-frame deletions were identified in 2 cases at a variant allele frequency of 52.16% and 50.91%, while the third case had an intronic CALR variant c.-48G>A at a variant allele frequency of 51.1%. Thus, CALR variants in all 3 cases were interpreted as potentially germline. Of the 228 cases that underwent JAK2 p.V617F and CALR cotesting in the past 2 years, only these 2 cases were positive for both JAK2 p.V617F and CALR exon 9 variants. Conclusions: These cases highlight the importance of understanding the pitfalls of molecular techniques in current practice.
AB - Objectives: The BCR::ABL1 negative myeloproliferative neoplasms are sequentially tested for JAK2 p.V617F, followed by CALR exon 9 pathogenic variants. Historically, these variants were thought to be mutually exclusive. However, recent reports indicate coexisting JAK2 p.V617F and CALR exon 9 somatic variants. Methods: Analysis of JAK2 p.V617F and CALR exon 9 variant was performed by polymerase chain reaction (PCR)–based assays. Subsequent testing was performed on the Genexus integrated sequencer (ThermoFisher) using the Oncomine myeloid assay GX v2. Results: CALR exon 9 variants were positive in 3 cases, while 2 were positive for JAK2 p.V617F on PCR-based assays. Next-generation sequencing confirmed the JAK2 P.V617F status in all cases. CALR variants resulting in in-frame deletions were identified in 2 cases at a variant allele frequency of 52.16% and 50.91%, while the third case had an intronic CALR variant c.-48G>A at a variant allele frequency of 51.1%. Thus, CALR variants in all 3 cases were interpreted as potentially germline. Of the 228 cases that underwent JAK2 p.V617F and CALR cotesting in the past 2 years, only these 2 cases were positive for both JAK2 p.V617F and CALR exon 9 variants. Conclusions: These cases highlight the importance of understanding the pitfalls of molecular techniques in current practice.
KW - CALR exon 9 variants
KW - germline vs somatic
KW - JAK2 V617F
KW - myeloproliferative neoplasm
KW - PCR-based testing
UR - http://www.scopus.com/inward/record.url?scp=85183954570&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=85183954570&partnerID=8YFLogxK
U2 - 10.1093/ajcp/aqad122
DO - 10.1093/ajcp/aqad122
M3 - Article
C2 - 37788380
AN - SCOPUS:85183954570
SN - 0002-9173
VL - 161
SP - 155
EP - 161
JO - American journal of clinical pathology
JF - American journal of clinical pathology
IS - 2
ER -