With the advent of techniques for biomolecular diagnosis the fight against onco-haematological pathologies can use efficient tools for the diagnosis and monitoring, based on technique of Poly- merase Chain Reaction (PCR), for the analysis of monoclonality, rearrangements, chromosomic translocations and for early and differential diagnosis, in addition to the evaluation of minimal residual disease (MRD). In the onco-haematologic pathologies specific chromosomic transloca- tions can be found and they can lead to fusion of genes coding for proteins with oncogenic prop- erties. These molecular alterations can be used as specific markers in the neoplastic cell; they can be searched in the nucleic acids (DNA and RNA) using Polymerase Chain Reaction (PCR) that allows to amply the neoplastic marker. This technique can be applied both for diagnosis, for better characterizing the pathology and define the prognosis, and for the study of the so called “minimal residual disease” (MRD), allowing to check if, once the patient has been treated, neo- plastic cells are still present .
The myeloproliferative neoplasms diseases (MPN) are one of the myeloid neoplasms according to the World Health Organization (WHO) classification. The Philadelphia-negative MPN are Polycythemia Vera (VP), Essential Thrombocytaemia (ET), Primary Myelo-Fibrosis (PMF) and Primary Myelo-Fibrosis in pre-fibrotic phase. These disorders are neoplastic diseases that affect staminal haematopoietic cells. In 2005 a point mutation has been identified (single nucleotide substitution G>T in 1849 nucleotide, with consequent substitution of valine residual with phe- nylalanine in position 617) in exon 14 of JAK2 gene, coding for a tyrosine-kinase (Janus Ki- nase2) involved in the intracellular signaling JAK-STAT. This mutation JAK2V617F can be found in almost all patients affected by Polycythemia Vera (95%), in a significant part of patients affected by Essential Thrombocytaemia (55%) and Primary Myelo-Fibrosis (65%). In the re- maining patients affected by Polycythemia Vera other mutations of JAK2 can be found. These mutation are concentrated on exon 12 .
Successively other somatic mutations in the MPL gene, coding for the thrombopoietin receptor, involved in the same way of intracellular signaling mediated by JAK-STAT. The mutations con- fer a functional gain to the mutated protein, being constitutionally active. The mutations of MPL gene found in MPN are mainly in the exon 10, involving the codon W515 (MPLW515 and MPLW515K), and shown in 4-5% of patients afflicted by Essential Thrombocytaemia and 7- 10% of the ones afflicted by Myelo-Fibrosis.
In the 2013 the mutation of CARL gene has been reported (coding for calreticulina) in the popu- lation of patients not showing mutations in JAK2 or MPL. The 80% of cases is constituted by mutation of type 1 (deletion of 52 bp) and mutation of type 2 (insertion of 5 bp). Anyway there some “triple negative” not showing any characterizing mutation for the neoplasia .