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.

Karl Landsteiner (1868-1943) was an Austrian-American biologist, physician, and immunologist whose groundbreaking discoveries revolutionized the fields of transfusion medicine, immunology, and virology. His most famous work was the identification of the ABO blood group system in 1901, which explained the causes of transfusion reactions and laid the foundation for safe blood transfusions. This discovery earned him the Nobel Prize in Physiology or Medicine in 1930. Landsteiner continued his research, identifying the MN and P blood group system in 1927 and the Rh blood group system in 1940, which addressed the complexities of the Hemolytic Disease of the Fetus and Newborn (HDFN). His work on the poliovirus in 1908, in collaboration with Erwin Popper, established the infectious nature of the disease and laid the groundwork for future vaccine development. Landsteiner's versatility as a scientist is evident in the breadth of his work, spanning hematology, immunology, and virology. His ability to navigate diverse fields and see connections between them allowed him to make pioneering discoveries that have had a lasting impact on medical practice, particularly in blood transfusion, organ transplantation, and immunotherapy. Landsteiner's legacy as the "Father of Transfusion Medicine" is reinforced by the standardization of blood typing procedures, which have saved millions of lives worldwide.

Hb Adana is a non-deletional α-thalassaemia variant, due to mutations in α1- or α2-globin codon 59 (αCD59) that produce unstable α-globin. Clinical appearance can range from silent carrier to blood transfusion reliance, hepatosplenomegaly, skeletal deformities, and spinal cord compression. Despite the importance of Hb Adana inheritance, this Hb variant is challenging to study since molecular tests are scarce and routine diagnosis can be missed. This study explored the distribution of Hb Adana among local high school students and evaluate the hematological parameters and haemoglobin analysis of Hb Adana in this region of Malaysia. This retrospective study included 13,721 blood samples from high school students enrolled in Malaysia's National Thalassaemia Screening Program at Hospital Raja Perempuan Zainab II (HRPZ II). Multiplex Gap PCR was used to detect deletional α-thalassaemia. Common non-deletional α-thalassaemia was detected using multiplex ARMS PCR. Evaluable data were retrieved from the HRPZ II database. Results: A total of 2327 subjects exhibited common deletional (n=1037, 44.6%) and non-deletional (n=1290, 55.4%) α-thalassaemia. Hb Constant Spring was the most frequent non-deletional α-thalassaemia. Thirty-one participants (1.33%) had αCD59α/αα and one (0.04%) had αCD59α/-α3.7. The 32 Hb Adana subjects were 87.5% Malay, and 12.5% Orang Asli. Additionally, seven cases of HbE/Hb Adana were discovered. The haemoglobin level in heterozygous Hb Adana ranged from mild anaemia to normal, 95.0 g/L to 153.0 g/L. The MCV and MCH were approximately 73 fL and 23 pg, respectively. Conclusions: We have denoted the distribution of alpha thalassaemia mutation patterns among high school students in Kelantan, Northeast Peninsular of Malaysia. Our observation showed Hb Adana was rarely uncommon in our region and the co-inheritance with an α-gene deletion generates α+-thalassaemia; with HbE, α0-thalassaemia. All heterozygous Hb Adana exhibited low MCVs and MCHs.