[Next generation sequencing in pediatric bone marrow failure: a valuable tool for accurate diagnosis].

Inherited Bone Marrow Failure syndromes account for approximately 25% of cases of aplastic anemia in pediatric patients. Next-generation sequencing (NGS) technologies have allowed the diagnosis of an increasing number of hereditary causes of bone marrow failure.

Objective: To determine the diagnostic yield and clinical concordance of NGS in the diagnosis of a cohort of pediatric patients with bone marrow failure.

Patients and method: Patients included were those aged between 0-17 years with a diagnosis of Bone Marrow Failure Syndrome according to the ICD-10 classification codes, who had undergone a genetic study between 2018 and 2022. The information was obtained from the electronic medical records system. Genomic DNA was isolated and quantified through the Qubit™ 3.0 fluorometer. Regions of interest were selected using a hybridization probe that included the intronic and exonic regions adjacent to the genes included in the panel. Clonal amplification and paired-end sequencing of the selected regions were performed using the Illumina MiSeq™ system. Bioinformatics analysis was performed in alignment with the reference genome (GRCh38). Variants classified as probably pathogenic or pathogenic were confirmed through Sanger sequencing.

Results: Out of 18 patients included, a genetic diagnosis was achieved through NGS in 5 (27.8%) of them: two cases of Fanconi Anemia, two cases of Dyskeratosis Congenita, and one case of TP53- associated bone marrow failure. Clinical concordance was 100%. Two novel variants were found in the FANCA and PARN genes as causing disease.

Conclusions: The use of NGS in patients with bone marrow failure identified the etiology in close to a third of patients of our cohort, with higher yield in patients with a clear clinical diagnosis and syndromic features.