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Introduction: Azacitidine is one of the hypomethylating agents available for the treatment of elderly patients with myelodysplastic syndrome (MDS) or acute myeloid leukemia (AML). It is also used as an appropriate treatment of chronic myelomonocytic leukemia (CMML) in the real life setting. As treatment of AML and CMML is not curative, and allogeneic stem cell transplantation (allo-SCT) remains traditionally the only option, significant clinical benefits by hypomethylating agents have been reported. According to the available data, 16% of subjects with MDS who received azacitidine had a complete or partial normalization of blood cell counts and bone marrow morphology, while two-thirds of patients who required blood transfusions no longer needed them. Nevertheless, it can also be hepatotoxic in patients with severe liver impairment and extensive liver tumors.

Gaucher disease (GD) is a multi-systemic disease with a low population frequency. It is a lysosomal storage disorder (LSD) that causes accumulation of glucocerebroside in the so called Gaucher cells predominantly in areas like the spleen, liver and bone marrow. Type I GD (GDI) is the most common form and usually does not involve the brain and the spinal cord. The symptoms can range from mild to severe and may appear anytime from childhood to adulthood. Diagnostics can often be challenging and imposes looking at person’s medical history, symptoms, physical exam, and laboratory test results. We present a difficult to diagnose case of a 34-year-old woman admitted to the Clinic of Hematology, “Sv. I. Rilski” hospital with splenomegaly, normal laboratory findings and non-enlarged liver. She didn’t show focal neurological symptoms. A series of tests were assigned including genetic targeted analysis. The case is an example of a rare genetic disease with mild clinical symptoms. Diagnosis of Gaucher disease, type I was confirmed by measurement of a GBA enzyme activity and identification of mutations in the GBA gene inherited in an autosomal recessive manner. Thanks to the efforts of the clinical team, the assignment of adequate clinical and laboratory tests and their correct interpretation, the patient was subjected to enzyme replacement therapy (ERT). Although the diagnosis was settled relatively late (at 34 years of age), the correct therapy slowed down the invalidation and improved the quality of life of the patient.

Myelofibrosis (MF) is characterized by a presence of an extra fibrous tissue in the bone marrow and additional hematopoiesis. The somatic mutation in the Janus kinase 2 (JAK2) gene (V617F) occurs gradually and is detected in about 50.0% of myelofibrosis or essential thrombo-cytopenia (ET) patients. Our aim was to determine the genotype status according to the carriers of the V617F mutation in patients with MF at the Hematology Ward of the University Hospital "Ivan Rilski" in Sofia, Bulgaria. DNA samples were isolated from venous blood of patients with various hematological disorders. DNA was amplified by polymerase chain reaction (PCR) and subsequent restriction analysis was performed using a BsaXI restriction enzyme. The genotype status was determined on 2.0% agarose gel. We analyzed 38 patients initially suspected of carrying MF or osteomyelofibrosis (OMF). After trepanobiopsy, 20 out of 38 patients were confirmed as myelofibrotic (52.6%), 5/38 (13.2%) were diagnosed as ET, 1/38 (2.6%) was diagnosed as myeloproliferative neoplasm (MPN), 6/38 (15.8%) had polycythemia vera (PV). In six patients, the presence of disease was rejected. Patients with MF were divided into three groups according to the JAK2 V617F genotype status: homozygous for the mutation (3/20 or 15.0%), heterozygous (9/20 or 45.0%) and homozygous for the wild type allele (8/20 or 40.0%). The triggering factor of MF is still unknown. It was considered that this factor could have a genetic nature. Mutations in three genes were mainly accepted as an actual predisposing events to this disease: point mutations leading to amino acid substitutions in JAK2 (V617F) and in MPL (W515L, W515K), as well as insertion or deletion in CALK We have proven that carriers of the V617F mutation prevailed in the group of patients with MF (altogether 12 patients or 60.0%). Previous studies also showed that JAK2 V617F is present in more than half of MF patients within their blood-forming cells. Therefore, the risk of evolution to MF could be associated with V617F-mutant allele burden in patients with MPN.