[Molecular diagnosis of clonality in B-precursor acute lymphoblastic leukemia of children using immunoglobulin heavy and kappa light chain gene rearrangements]

Enormous diversities of heavy chain immunoglobulin [IgH] and IgK molecules are generated during B- and T-lymphocyte differentiation through the rearrangement of gene segments. Additionally, random insertion and deletion of nucleotides between gene segments make unique sequences which are cell or clone specific. IgH and IgK gene rearrangements are the most and relatively common reported rearrangements in B-precursor acute lymphoblastic leukemia, respectively. The purpose of this study is to evaluate the pattern of IgH and IgK gene rearrangements using polymerase chain reaction [PCR] in BP-ALL in Iranian children. For this prospective study, bone marrow aspirates of 183 patients with the diagnosis of acute leukemia were collected at admission before any chemotherapy. Having reviewed cytomorphology [L[1]:44%, L[2]:41%] and immunophenotyping, only 140 cases with the diagnosis of B-precursor ALL were selected. Mononuclear cells including leukemic blasts were isolated by density gradient. Having DNA extracted, hyper-variable regions of IgH and IgK were amplified by consensus primers using PCR. PCR products were analyzed after heteroduplex analysis and polyacrylamide gel electrophoresis [silver stain]. The DNA sequences were compared and aligned to the sequences homologous for IgH and IgK published by Gene Bank. IgH gene rearrangements were found in 114 [90.4%] of patients using consensus primers for CDR-III and CDR-I regions [monoclonal 57.8% biclonal 34.9% oligoclonal 5.5%]. Four of nine patients with T-ALL had clonal rearrangements of IgH. Clonal pattern of Ig?-Kde were present in 59 [67%] of cases [biclonal 10%]. VKI [25%] and VK? [22.7%] were the most common type of rearrangements. Clonal rearrangement pattern of IgH gene was similar to other populations. Using FRI and FRIII primers in multiplex PCR increased the rate of detection and reducing turnaround time. IgK was slightly more frequent than previous reports while VKI [25%] was the most common type

Determining the mutation and the first reports of May Hegglin anomaly from Iran and the first homozygous E1841K mutations in the world

May-Hegglin anomaly [MHA] is a rare autosomal disorder which is characterized by triad of thrombocytopenia, giant platelets and Dohle like inclusion bodies in granulocytes. This is the first report of MHA and its mutation from Iran. The specimen of two patients [father 51 and son 15 y/o] collected with EDTA and tri-sodium citrate anticoagulants. CBC and peripheral blood smear studied by automatic cell counter and microscopic examination, respectively. Direct sequencing of extracted DNA of certain exons of MYH9 gene was performed. Both patients had demonstrated the diagnostic triad of MHA. Mutations showed homozygous and heterozygous pattern in the father and the son, respectively. This is the first report of MHA from Iran. The mutation of both patients was E1841K which is the most common type among MYH9 mutations in MHA. The most interesting finding was the homozygous mutation that did not entail any clinical severity