Bolou K, Kapsimali Z, Dettoraki A, Michalopoulou K, Triantafyllou G, Karangeli N, Piagkou M, Pergantou H. Molecular pathogenesis and therapeutic advances in haemophilia, an update of the current evidence. World J Hematol 2026; 12(2): 121492 [DOI: 10.5315/wjh.121492]
Corresponding Author of This Article
George Triantafyllou, Department of Anatomy, School of Medicine, Faculty of Health Sciences, National and Kapodistrian University of Athens, 75 Mikras Asias Street, Goudi, Athens 11527, Attikí, Greece. georgerose406@gmail.com
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Hematology
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Bolou K, Kapsimali Z, Dettoraki A, Michalopoulou K, Triantafyllou G, Karangeli N, Piagkou M, Pergantou H. Molecular pathogenesis and therapeutic advances in haemophilia, an update of the current evidence. World J Hematol 2026; 12(2): 121492 [DOI: 10.5315/wjh.121492]
World J Hematol. Sep 10, 2026; 12(2): 121492 Published online Sep 10, 2026. doi: 10.5315/wjh.121492
Molecular pathogenesis and therapeutic advances in haemophilia, an update of the current evidence
Konstantina Bolou, Zoey Kapsimali, Athina Dettoraki, Katia Michalopoulou, George Triantafyllou, Nektaria Karangeli, Maria Piagkou, Helen Pergantou
Konstantina Bolou, School of Medicine, Faculty of Health Sciences, National and Kapodistrian University of Athens, Athens 11527, Attikí, Greece
Zoey Kapsimali, Athina Dettoraki, Katia Michalopoulou, Helen Pergantou, Haemophilia Centre, Haemostasis and Thrombosis Unit, “Aghia Sophia” Children’s Hospital, Athens 11527, Attikí, Greece
George Triantafyllou, Nektaria Karangeli, Maria Piagkou, Department of Anatomy, School of Medicine, Faculty of Health Sciences, National and Kapodistrian University of Athens, Athens 11527, Attikí, Greece
Author contributions: Bolou K, Kapsimali Z, Dettoraki A and Pergantou H were responsible to conceptualization; Bolou K, Triantafyllou G and Piagkou M were responsible to methodology; Dettoraki A, Michalopoulou K and Pergantou H were responsible to validation; Bolou K, Kapsimali Z, Triantafyllou G and Karangeli N were responsible to formal analysis; Bolou K, Triantafyllou G and Karangeli N were responsible to investigation and writing—original draft preparation; Dettoraki A, Michalopoulou K, Piagkou M and Pergantou H were responsible to data curation; Kapsimali Z, Dettoraki A, Michalopoulou K, Piagkou M and Pergantou H were responsible to writing—review and editing; Piagkou M and Pergantou H contributed to supervision; all authors have read and agreed to the published version of the manuscript.
Conflict-of-interest statement: The authors declare that they have no conflict of interest.
Corresponding author: George Triantafyllou, Department of Anatomy, School of Medicine, Faculty of Health Sciences, National and Kapodistrian University of Athens, 75 Mikras Asias Street, Goudi, Athens 11527, Attikí, Greece. georgerose406@gmail.com
Received: March 26, 2026 Revised: April 8, 2026 Accepted: April 24, 2026 Published online: September 10, 2026 Processing time: 166 Days and 18.8 Hours
Abstract
Haemophilia A and B are X-linked inherited bleeding disorders caused by quantitative or qualitative deficiencies of coagulation factors VIII and IX, respectively. Understanding the underlying genetic pathogenesis and its variants is of paramount importance for current treatment targets, such as gene therapy. The current comprehensive review synthesizes the current evidence of molecular pathogenesis of haemophilia A and B, while it presents the therapeutic strategies, their limitations and future directions. Advances in molecular genetics have defined a highly heterogeneous mutational spectrum. Recurrent F8 inversions (intron 22 and 1) dominate severe phenotypes, while null mutations (nonsense, frameshift) are strongly associated with increased inhibitor risk. Conversely, missense variants predominantly underlie mild-to-moderate forms, and the identification of gain-of-function variants has directly informed next-generation therapeutic design. Clinically, strategies have transitioned from episodic replacement to individualized prophylaxis with ultra-long-acting concentrates and non-factor mimetics (emicizumab), which effectively prevent joint disease even in the presence of inhibitors. Furthermore, adeno-associated viral-mediated gene therapy offers a path toward a functional cure through sustained endogenous factor expression, although the long-term durability of FVIII expression and hepatic safety remain the primary current challenges. This review bridges the gap between the complex molecular landscape of haemophilia and the latest therapeutic breakthroughs. By linking specific genotypes to clinical outcomes and inhibitor risk, it provides a framework for precision management using factor, non-factor, and gene-based strategies in the current clinical landscape.
Core Tip: The current comprehensive review synthesizes the current evidence of molecular pathogenesis of haemophilia A and B, while it presents the therapeutic strategies, their limitations and future directions. Advances in molecular genetics have defined a highly heterogeneous mutational spectrum in F8 and F9, including recurrent inversions, point mutations, small insertions or deletions, and large rearrangements. These variants underlie genotype-phenotype correlations. Therapeutic strategies have evolved from on-demand plasma-derived factor replacement to individualized prophylaxis with standard and extended half-life concentrates. Parallel progress in liver-directed adeno-associated viral gene therapy has enabled sustained endogenous expression of FVIII and FIX following a single infusion, with marked reductions in annualized bleeding rates and factor use.
