Characterisation of a new familial amyotrophic lateral sclerosis

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Spectrum of BCR-ABL1 kinase domain mutations: A cohort study from Saudi Arabia

Background: The BCR-ABL1 tyrosine kinase domain mutation constitutes a major cause of resistance to the tyrosine kinase inhibitors in patients with chronic myeloid leukemia (CML). In this retrospective study, we assessed the ABL kinase domain mutation in 123 patients (61 females and 62 males) aged 10–79 years (median age of 50 years). These patients were referred to our clinics at King Faisal Specialist Hospital and Research Center (General Organization), Riyadh, Kingdom of Saudi Arabia during period (2011–2014). These patients had Philadelphia-positive CML displaying either failure to tyrosine kinase inhibitor (TKI) or suboptimal response with increased BCR-ABL1 levels through serial monitoring by using quantitative Real time PCR. Methods: The mutation analysis was performed on RNA extracted from Peripheral blood samples after the amplification of the BCR-ABL1 transcript by nested PCR followed by direct sequencing of the BCR-ABL1 kinase domain including the residues (243–487). Results: Of 123 patients, 119 adults and four pediatrics were analyzed. From the total, 25 (20%) were tested positive for 11 different mutations in the ABL1 kinase domain (11 patients with T315I, 3 with Y253H, 2 with E255K, 2 F317L, and 1 patient having each of the following mutations: F359I, E355G, V299L, L248V, L298, M244V, and Y326H). The duration from the diagnosis to mutation detection ranged between 3 and 144 months with a median duration of four years. Conclusion: Despite the retrospective nature of the study and relatively small sample size of a single center analysis, the mutation frequency is in line with similar reported studies from other parts of the world

Spectrum of BCR-ABL Kinase Domain Mutations; A Cohort Study from Saudi Arabia

Abstract Chronic myeloid leukemia (CML) is a clonal myeloproliferative neoplasm (MPN) associated with a characteristic translocation between chromosome 9 and 22 to form Philadelphia chromosome (Ph). The introduction of tyrosine kinase inhibitors (TKIs) imatinib for CML marked a new era for targeted therapy. In general CML patients in chronic phase (CP) have a very good response to Imatinib with a ~85% projected overall rate of survival. However, a significant proportion harbor molecular residual disease and develop acquired resistance after initial response through a number of cellular and molecular mechanisms in which mutations in the Abl kinase domain are the best known cause of resistance. Mutations are detected in 35% of patients with resistance to TKI in Chronic Phase and up to 80% in patients with accelerated phase and blast phase. Given the clinical importance of the mutation status, mutation analysis was established as a clinical service to aid in the clinical decision and identify the subset who would benefit from alternative therapies. In this retrospective study, we assessed the ABL kinase domain mutation in 93 patients referred from our clinics at King Faisal Specialist Hospital and Research centre (General Organization) between 2011-2013 with Ph positive CML displaying either refractory to TKI or resistance displaying increase BCR-ABL1 levels by serial monitoring using Quantitative PCR. Mutation analysis was performed on RNA extracted from either blood or Bone marrows after amplification of the BCR/ABL1 transcript by nested PCR followed by Direct sequencing of the BCR-ABL1 Kinase domain including residues 243-487. In total, 93 patients (46 Females and 47 males), Age between 10-71 years (median age: 38 years) of which 89 were adults and 4 pediatrics were analyzed. Among 93 patients, 20 (21.5%) were positive for 10 different mutations across the ABL1 Kinase domain mutations (7 patients had T315I, 3 patients had each of the following mutation: Y253H, F359I, 2 patients with E255K. Additionally, one patient with each of the following mutations: E355G, V299L, L248V, L298, Y326H and F317L). The duration from diagnosis to mutation detection ranged between 3-144 months with a median duration of 4 years. Despite the retrospective nature and the relatively small sample size of a single center analysis, the mutation frequency is in line with similar studies reported from our region. Further follow up is needed to identify the outcome of these patients acquiring ABL kinase mutations on targeted therapy. Disclosures No relevant conflicts of interest to declare. </jats:sec

Cytogenetics and molecular markers of acute myeloid leukemia from a tertiary care center in Saudi Arabia

Background/Purpose: Acute myeloid leukemia (AML) is a phenotypically and genetically heterogeneous disease. This heterogeneity is attributed to alterations in genetic bases. AML classification based on these abnormalities is essential for accurate diagnosis, risk stratification, prognostic value, monitoring of minimal residual disease, and developing targeted therapies. This study evaluates frequency of each karyotype and molecular abnormality at our institution with comparison to other international studies. Materials and Methods: We reviewed 100 bone marrow samples, which represent all AML diagnosed cases at our hospital from 2012 to 2014 by conventional karyotyping, specific AML–FISH panel, and variety of AML-specific mutations using Sanger sequencing. Results: Out of 100 AML patients investigated with median age of 29 years, 98 were successfully karyotyped, and 64% of cases had an abnormality. In addition, all 100 AML–FISH panel and molecular studies were informative with an abnormality reaching 50 and 45%, respectively. Conventional and molecular cytogenetic studies revealed trisomy 8 (15%), t(8;21) in 12%, trisomy 21(8%), inv(16) in 7%, t(15;17) in 6%, 11q rearrangements (6%), and inv(3) in 2%. The mutational analysis showed nucleophosmin 1 (12%), FMS-like tyrosine kinase-3–internal tandem duplication (9%), IDH2 (7%), IDH1 (6%), WT1 (5%), DNMT3A (4%), CEBPA (4%), and c-KIT (3%). Conclusion: The incidence of most mutational analysis is lower, whereas abnormal karyotype showed almost similar frequency when compared to different international centers. This is the first cytogenetic data from Saudi Arabia for AML, including all these genetic mutations. Therefore, a multicenter collaboration and comprehensive study is recommended to confirm these findings

Comprehensive Analysis of JAK2 Mutations: A Single Center Experience

Abstract Mutations in Janus kinase 2 (JAK2) genes are the genetic hallmark of BCR-ABL1-negative myeloproliferative neoplasms (MPN). In 2005 several groups described a point mutation in codon 617 of the protein tyrosine kinase (JAK2 gene) in BCR-ABL1-negative MPN. The mutation was found in a vast majority of patients with polycythemia vera (PV), in approximately half of patients with essential thrombocythaemia (ET) and in myelofibrosis (MF). In 2007, an additional exon 12 mutation were found in a small percentage of PV patients. The 2008 World Health Organization classification of haematopoietic neoplasms includes JAK2 mutations as one of the strongest diagnostic criteria for PV and together with the MPLmutations for ET and PMF. In this study, we describe the JAK2 mutation profile in a series of 1811 samples collected over the period of 48-months (2010-2013). The samples were submitted from patients h thrombosis or clinically suspected for having MPN to the Molecular laboratory at King Faisal specialist Hospital &amp; Research center, Riyadh, Saudi Arabia. A comprehensive analysis of exons 12-15 was carried using Sanger sequencing method. Of the 1811 samples, 1706 samples were available for analysis. JAK2 mutations was identified in 271 (16%) of the samples. We evaluated the positive cases for the following: age, gender, type of JAK2mutation, if the patients are evaluated for other genetic mutations and diagnosis. Of these 271 positive cases; 148 (54.6%) were females and 123 (45.4%) males. 103 (38%) cases were from inside the hospital while 168 (62%) cases were from different referring institutions in which the diagnosis was not available. Their age varied between 4 months and 97 years with a median of 54 years. A total of 262 (96.7%) patients were positive for JAK2 V617F; In the remaining 9 (3.3%) samples non V617F mutation were detected, in which 5 (1.8%) cases with JAK2 G571S, 1 case (0.3%) with JAK2 p.E543_D544del, 1 (0.3%) case with JAK2 p.Y570Y, 1 (0.3%) with JAK2 exon 12 deletion (p.R541_E543&gt;K) and 1 (0.3%) with JAK2 del (540I - 542N), ins M. of the 271, 13 (5%) cases were associated with other cytogenetic or DNA Sequence abnormalities together with the JAK2mutation. Of the 13, 4 cases (1.4%) presented with Abnormal karyotype, 5 (1.8%) with a heterozygous Methylenetetrahydrofolate reductase (MTHFR) polymorphism, 3 (1.1%) cases with BCR/ABL1 and 1 case has a missense mutation p.V726A, in exon 10 of the MEFV gene. The positive in-house cases tested for JAK2mutation were 103 (38%). Clinical diagnosis included: 87 (84.4%) MPN cases of which 35 (40.2%) PV, 22 (25.3%) ET, 11 (12.6%) MF, 17 (19.5%) unclassifiable MPN, 2 (2.3%) CML. Moreover, 9 (8.7%) Budd-Chiari syndrome, 6 (5.8%) thrombosis (including DVT, PE and portal thrombosis) and 1 (0.9%) squamous cell carcinoma. In our study 1811 sample were tested in 4 years which means almost 1 sample is submitted daily for JAK2 testing in our institute. The Majority of the in-house patients tested were MPN patients with small percentage having thrombosis which could progress later to full MPN clone. Over 50 different non-V617F mutations have been identified in the literature and were presented by a small portion of our patients cohort. It was shown to have biologic effects similar to those caused by the V617F mutation; however, more research in this area is ongoing. Disclosures No relevant conflicts of interest to declare. </jats:sec

A New Familial Amyotrophic Lateral Sclerosis Locus on Chromosome 16q12.1-16q12.2

Familial amyotrophic lateral sclerosis (FALS) affects 5%–10% of cases of amyotrophic lateral sclerosis (ALS) and is inherited as an autosomal dominant condition with incomplete penetrance. One-fifth of these cases of FALS are associated with mutations in copper/zinc-dependent superoxide dismutase (SOD1), but the gene defect in the remaining 80% of familial cases is, as yet, unknown. We have carried out a preliminary genome screen, using a U.K. resource of families lacking SOD1 mutations, to identify other potential disease loci and have identified a putative locus on chromosome 16q12.1-q12.2. The region associated with disease was further refined in the major family that contributed to this result and was localized to D16S409–D16S3032, a 14.74-cM genetic interval that corresponds to a physical distance of 6.6 Mb, which coincides with a region independently identified by two further research groups in the United States and the United Kingdom

Molecular patterns of β-thalassemia mutations of Saudi patients referred to King Faisal Specialist Hospital and Research Center

Background: Beta thalassemias are a group of hereditary blood disorders that are characterized by reduction or complete absence of the β-globin chain synthesis due to mutations, affecting critical areas of the β-globin gene on the chromosome 11. The disease is inherited in an autosomal recessive manner, with severity ranging from asymptomatic individuals to transfusion dependent anemia, according to the nature of the mutation. The prevalence of the β-globin gene in various areas of Saudi Arabia, previously reported as 0.01 to 0.15% in general population. Materials And Methods: A cohort of 131 samples, which were submitted for β-globin gene mutation analysis in King Faisal Specialist Hospital and Research Center during 2008 to 2013, were tested for the entire genomic region (3-Exons and 2-Introns) of the HBB gene by direct Sanger sequencing technique. Results: Out of the total population tested, 28 (21%) were undetectable cases and 103 (79%) were detectable for β-globin chain mutations. Nineteen different mutations of the HBB gene were identified in all detectable cases (103 patients). Among these mutations c.315+1G>A, c.118C>T, and c.92+5G>C were detected in the majority of cases (66%) with five novel mutations (c.410G>A, c.-151C>T, c.68_74delAAGTTGG, c.316-3C>A, and c.-31C>T) that are reported for the first time in Saudi population. Discussion: The result of this retrospective study confirms the previously reported common β-thalassemia mutations among Saudi population