[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.

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

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.

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.

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.