66. Screening for genetic predisposition to pediatric leukemia in a Peruvian population

Aly Abdelkareem

Jeny Bazalar-Montoya

I am a medical geneticist currently working at the Instituto Nacional de Salud del Niño-San Borja (INSN-SB) in Peru. Since obtaining my specialty in medical genetics in 2019, I worked at the Neurogenetics Research Center of the National Institute of Neurological Sciences (INCN) where I implemented the predictive testing program for Huntington’s disease and have collaborated in the implementation of the first DNA biobank for research purposes in Peru. I completed a Master of Science in Epidemiological Research program at the Universidad Peruana Cayetano Heredia-Peru. I have worked in the implementation of the NGS panel for somatic and germline leukemia for children with leukemia at INSN-SB. I am very proactive I enjoy learning and making new things and I like to challenge myself to see how much more I can accomplish.

Abstract

Jeny Bazalar-Montoya, Richard S. Rodriguez, Francisco Sanchez-Pinto, Julissa Fuentes-Vera, Guillermo Romero-Guerra, Monica Correa-Guerrero, Ricardo Abanto-Hinostroza, Sergio Murillo-Vizcarra, Victoria Godoy-Vila, Gioconda Manassero-Morales

Instituto Nacional de Salud del Niño-San Borja, Lima, Peru

Background: Genetic predisposition to pediatric leukemias is variable among populations. Pathogenic/likely pathogenic (P/LP)  variants increase the risk of developing hematologic malignancies that can be identified by massive sequencing (NGS). Peru has one of the highest incidence and mortality rates for pediatric leukemia in Latin America. Our aim was to determine the frequency of genetic predisposition to pediatric leukemia in the Peruvian population.

Methods: Genomic DNA extraction from peripheral blood  and sequencing of 200 genes predisposing to hematological malignancies was performed. All pediatric patients diagnosed with pediatric  leukemia at a reference institute in Peru between 2021 and 2022 were enrolled after complete remission of leukemia.

Results: A total of 192 unrelated patients were analyzed (158 B-ALL, 7 T-ALL, 10 AML, 5 JMML, 8 APL, 2 CML, 2 Mixed Leukemia). We observed 11 patients with P variants and 7 patients with LP variants. The most relevant P/LP variants were in CDKN2A, CHEK2, MEFV1, PALB2, PTPN11 and RAD50 genes in B-ALL; ATM in T-ALL; PTPN11, CBL and KRAS in JMML. Furthermore, we detected V804M RET in two patients with B-ALL.

Conclusions: We detected P/LP variants in about 10% of pediatric patients. However, we did not detect pathogenicity in the PAX5, ETV6, TP53 and IKZF1 genes previously reported. We consider this first approach to the identification of genetic predisposition to pediatric leukemias in Peru to be relevant. Even so, a larger cohort will be needed to clarify the germline genetic picture for pediatric leukemias in our population.