Mutations in Genes Associated with Familial Predisposition to Myeloid Neoplasms: Their Frequency and Associations with Pretreatment Characteristics in Adult Patients (Pts) with Presumably Sporadic De Novo Acute Myeloid Leukemia (AML)

• Published in: Blood 2018-11, Vol.132 (Supplement 1), p.1478-1478
• Main Authors: Eisfeld, Ann-Kathrin, Kohlschmidt, Jessica, Mrózek, Krzysztof, Mims, Alice S., Walker, Christopher J., Nicolet, Deedra, Blachly, James S., Genutis, Luke K, Carroll, Andrew J., Powell, Bayard L., Kolitz, Jonathan E., Stone, Richard M., de la Chapelle, Albert, Byrd, John C., Bloomfield, Clara D.
• Format: Article
• Language: English
• ISSN: 0006-4971; 1528-0020
• DOI: 10.1182/blood-2018-99-120085

The effects of germline variants in the development of myeloid neoplasms, including AML, were largely neglected for decades. However, several myeloid neoplasms with germline predisposition have been recently recognized as separate entities in the 2016 revision to the World Health Organization (WHO) classification of myeloid neoplasms and acute leukemia. In addition to genes whose mutations are associated with bone marrow failure syndromes, and are long-known contributors to Mendelian disorders that have myelodysplastic syndromes/AML as the main clinical feature (e.g., germline CEBPA, GATA2 and RUNX1 mutations), 3 more genes were included: ANKRD26, DDX41 and SRP72. Mutations in these genes were described in few families, and are thus considered to be very rare. However, it is possible that their frequency might be underestimated, because the associated phenotypes are often vague and family history not routinely considered. To establish the frequency of ANKRD26, DDX41 and SRP72 mutations, and to characterize molecular and clinical features associated with these mutations, we determined mutational status of 83 cancer- and leukemia-associated genes using 2 targeted sequencing panels in diagnostic samples of 1,021 clinically well-characterized adult pts with de novo AML AML treated on trials conducted by the Alliance for Clinical Trials in Oncology. Mutations in the 3 familial genes were found in 46 pts (4.5%), specifically, mutations in ANKRD26 in 15, DDX41 in 17 and SRP72 in 19 pts. Three pts had mutations in either 2 or all 3 genes. Mutations occurred at varying variant allele fractions (VAFs, median: 0.47; range: 0.10-0.98), with 76% of mutations observed with VAFs >35%. Mutations were found throughout the genes. Pts harboring mutations in any of the 3 genes were predominantly younger (median age, 54 years; range, 19-77), 65% of them were male, and 48% belonged to the 2017 European LeukemiaNet (ELN) favorable genetic risk group. The co-mutation profiles partially differed among the genes. NPM1 mutations were the most frequent co-mutations, occurring in 47%, 41%, and 42% of pts with mutations in ANKRD26, DDX41, and SRP72, respectively. However, ANKRD26-mutated pts frequently harbored FLT3-ITD and mutations in DNMT3A, IDH2 and SRSF2 genes (each detected in 20% of pts). DDX41-mutated pts commonly had mutations in NRAS (18%), SMARCA2 (12%) and TP53 (12%). SRP72-mutated pts often had mutations in TET2 (26%), CEBPA (23%) and IDH1 (21%). With the exception of a hi