Two Novel Mutations of the NPM1 Gene in Syrian Adult Patients with Acute Myeloid Leukemia and Normal Karyotype.

OBJECTIVE: Somatic mutations in exon 12 of the NPM1 gene is one of the most common genetic abnormalities in adult acute myeloid leukemia (AML), which is observed in 25-35% of AML patients and in 50-60% of patients with cytogenetically normal AML (CN-AML). METHODS: We performed Sanger sequencing of exon 12 of the NPM1 gene, on 44 CN-AML patients to characterize NPM1 status. RESULTS: In this study, NPM1 mutations were identified in 10 (22.7%) of the 44 CN-AML patients. Among the 10 patients with NPM1 mutations, type A NPM1 mutations were identified in 8 (80%) patients, whereas non-A type NPM1 mutations were observed in 2 (20%) patients. Two non-A type NPM1 mutations were not previously reported: c.867-868InsCGGA and c.861-862InsTGCA. These two novel mutant proteins display a nuclear export signal (NES) motif (L-xxx-L-xx-V-x-L) less frequently and L-x-Lx-V-xx-V-x-L it has been never seen before, yet. However, both novel mutations show a tryptophan loss at codon 288 and 290 at the mutant C-terminus which are crucial for aberrant nuclear export of NPM into the cytoplasm. CONCLUSIONS: This study suggests previously unreported NPM1 mutations may be non-rare and thus additional sequence analysis is needed along with conventional targeted mutational analysis to detect non type-A NPM1 mutations.

Bloom syndrome with myelodysplastic syndrome that was converted into acute myeloid leukaemia, with new ophthalmologic manifestations: the first report from Syria.

Bloom syndrome is a rare autosomal recessive disease, in which BLM gene is mutated, leading to genome instability and proneness to malignancy. It is characterized by short stature, sun-sensitive rash and immunodeficiency. We present a case of bloom syndrome with myelodysplasia complicated by acute myeloid leukaemia. This case has new ophthalmologic manifestations. We confirmed the diagnosis by detection of high rate of sister chromatid exchange. The patient received chemotherapy but did not tolerate it well and developed fungal pneumonia.

A new adult AML case with an extremely complex karyotype, remission and relapse combined with high hyperdiploidy of a normal chromosome set in secondary AML.

BACKGROUND: Chromosomal abnormalities are diagnostic and prognostic key factors in acute myeloid leukemia (AML) patients, as they play a central role for risk stratification algorithms. High hyperdiploidy (HH), a rare cytogenetic abnormality seen commonly in elder male AML patients, is normally categorized under AML with complex karyotype (CK). Accordingly, patients with HH generally are associated with low remission rates and a short overall survival. CASE PRESENTATION: Here we report a case of 21-year-old female, diagnosed with a de novo AML-M1 according to WHO classification and a CK at diagnosis. Cytogenetic, molecular cytogenetic approaches (standard fluorescence in situ hybridization (FISH), array-proven multicolor banding (aMCB)) and high resolution array comparative genomic hybridization (aCGH) analyses revealed a unique complex but still near diploid karyotype involving eleven chromosomes was identified. It included pentasomy 4, three yet unreported chromosomal aberrations t(1;2)(p35;p22), t(1;3)(p36.2;p26.2), and t(10;12)(p15.2;q24.11), and a combination of two cytogenetic events, yet unreported to appear in together, i.e. a reciprocal translocation t(1;3)(p36.2;p26.2) leading to EVI1/PRDM16 gene fusion, and monoallelic loss of tumor suppressor gene TP53. After successful chemotherapeutic treatment the patient experienced a relapse to AML-M1, and she developed secondary AML-M6 with tetraploidy and HH. Unfortunately, the young woman died 8.5 months after initial diagnosis. CONCLUSIONS: To the best of our knowledge, a comparable adult AML associated with such a CK, coexistence of 3q rearrangements with loss of TP53 at diagnosis, and HH in secondary AML were not previously reported. Thus, the combination of the here seen chromosomal aberrations in adult primary AML seems to indicate for an adverse prognosis.