Hematological Profile of Hb Adana Among High School Students in Northeast Peninsular Malaysia.

Background Hb Adana is a non-deletional alpha (α)-thalassaemia variant resulting from mutations in α1- or α2-globin codon 59 (αCD59), leading to the production of unstable α-globin. Clinical manifestations can vary from silent carrier status to dependence on blood transfusions, hepatosplenomegaly, skeletal deformities, and spinal cord compression. Despite the significance of Hb Adana inheritance, studying this variant poses challenges due to the scarcity of molecular tests and the potential for routine diagnoses to be overlooked. This study aims to investigate the prevalence of Hb Adana among local high school students and assess the hematological parameters and hemoglobin analysis of Hb Adana in Malaysia. Methodology This retrospective study analyzed 13,721 blood samples collected from high school students participating in Malaysia's National Thalassaemia Screening Program at Hospital Raja Perempuan Zainab II (HRPZ II). Deletional α-thalassaemia was detected using multiplex gap-polymerase chain reaction (PCR), while common non-deletional α-thalassaemia was identified using multiplex amplification refractory mutation system (ARMS) PCR. Data were extracted from the HRPZ II database for analysis. Results Among the participants, 2327 individuals were found to have either common deletional (n=1037, 44.6%) or non-deletional (n=1290, 55.4%) α-thalassaemia. Hb Constant Spring was the most prevalent non-deletional α-thalassaemia, accounting for 53.03% of cases. Thirty-one participants (1.33%) exhibited αCD59α/αα, and one (0.04%) had αCD59α/-α3.7. Among the 32 subjects with Hb Adana, 87.5% were Malay, and 12.5% were Orang Asli. Additionally, seven cases of HbE/Hb Adana co-inheritance were identified. Hemoglobin levels in heterozygous Hb Adana individuals ranged from mild anemia to normal, between 95 g/L and 153 g/L. Mean corpuscular volume (MCV) and mean corpuscular hemoglobin (MCH) were approximately 73 fL and 23 pg, respectively. Conclusion This study delineates the distribution of α-thalassaemia mutation patterns among high school students in Kelantan, Northeast Peninsular Malaysia. Our findings indicate that Hb Adana is rare in our region and co-inheritance with an α-gene deletion results in α+-thalassaemia and with HbE, α0-thalassaemia. All heterozygous Hb Adana individuals exhibited low MCVs and MCHs.

Molecular Genetics of Thrombotic Myeloproliferative Neoplasms: Implications in Precision Oncology.

Classical BCR-ABL-negative myeloproliferative neoplasms (MPN) include polycythaemia vera, essential thrombocythaemia, and primary myelofibrosis. Unlike monogenic disorders, a more complicated series of genetic mutations are believed to be responsible for MPN with various degrees of thromboembolic and bleeding complications. Thrombosis is one of the early manifestations in patients with MPN. To date, the driver genes responsible for MPN include JAK2, CALR, MPL, TET2, ASXL1, and MTHFR. Affords have been done to elucidate these mutations and the incidence of thromboembolic events. Several lines of evidence indicate that mutations in JAK2, MPL, TET2 and ASXL1 gene and polymorphisms in several clotting factors (GPIa, GPIIa, and GPIIIa) are associated with the occurrence and prevalence of thrombosis in MPN patients. Some polymorphisms within XRCC1, FBG, F2, F5, F7, F12, MMP9, HPA5, MTHFR, SDF-1, FAS, FASL, TERT, ACE, and TLR4 genes may also play a role in MPN manifestation. This review aims to provide an insightful overview on the genetic perspective of thrombotic complications in patients with MPN.

Conformation sensitive gel electrophoresis for the detection of calreticulin mutations in BCR-ABL1-negative myeloproliferative neoplasms.

INTRODUCTION: Calreticulin (CALR) mutations in myeloproliferative neoplasms (MPN) have been reported to be key markers in the molecular diagnosis, particularly in patients lacking JAK2 V617F mutation. In most current reports, CALR mutations were analysed by either allele-specific PCR (AS-PCR), or the more expensive quantitative real-time PCR, pyrosequencing and next-generation sequencing. Hence, we report the use of an alternative method, the conformation sensitive gel electrophoresis (CSGE) for the detection of CALR mutations in BCR-ABL1-negative MPN patients. METHODS: Forty BCR-ABL1-negative MPN patients' DNA: 19 polycythemia vera (PV), 7 essential thrombocytosis (ET) and 14 primary myelofibrosis (PMF), were screened for CALR mutations by CSGE. PCR primers were designed to amplify sequences spanning between exons 8 and 9 to target the mutation hotspots in CALR. Amplicons displaying abnormal CSGE profiles by electrophoresis were directly sequenced, and results were analysed by BioEdit Sequence Alignment Editor v7.2.6. CSGE results were compared with AS-PCR and confirmed by Sanger sequencing. RESULTS: CSGE identified 4 types of mutations; 2 PMF patients with either CALR type 1 (c.1099_1150del52) or type 2 (c.1155_1156insTTGTC), 1 ET patient with nucleotide deletion (c.1121delA) and insertion (c.1190insA) and 1 PV patient with p.K368del (c.1102_1104delAAG) and insertion (c.1135insA) inframe mutations. Three patients have an altered KDEL motif at the C-terminal of CALR protein. In comparison, AS-PCR only able to detect two PMF patients with mutations, either type 1 and type 2. CONCLUSION: CSGE is inexpensive, sensitive and reliable alternative method for the detection of CALR mutations in BCR-ABL1-negative MPN patients.