A novel homozygous nucleotide deletion at JAK�2 gene in a pediatric B-cell precursor acute lymphoblastic leukemia

Janus kinase 2 (JAK2) is a protein tyrosine kinase that transduces cellular signals through the Janus kinase signal transducer and an activator of transcription pathways (JAK-STAT), which mediates cell growth, differentiation, apoptosis, transformation, and other fundamental cell functions, and is active in both normal hematopoiesis and hematological malignancies. Tyrosine kinase protein mutations are important in the development of malignant processes. JAK2 mutations have been identified in myeloproliferative disorders, of which exon 14 V617F mutation is the most common. Other novel mutations were identified in exon 12, which is located at the proximal region of the gene. These reported mutations impair the organization of JAK2 kinase activity [1-4]. Herein, we report a novel homozygous “G” deletion at exon 12 of the JAK2 gene in a pediatric patient with acute lymphoblastic leukemia (ALL).