Monica Bessler, MD, PhD

Locations: Main Campus
Appointments and Referrals: 1-800-TRY-CHOP (1-800-879-2467)

  • Background

    Dr. Bessler is currently the Director of The Pediatric and Adult Comprehensive Bone Marrow Failure Center at the Children’s Hospital of Philadelphia and the Perelman School of Medicine University of Pennsylvania Health System in Philadelphia, PA.

    Prior to her current position, she was Professor in Internal Medicine and Professor in Molecular Biology and Pharmacology at Washington University School of Medicine in St. Louis, MO.

    Dr. Bessler received a physician’s degree from the Medical School of the University of Zurich, Switzerland in 1981 and her medical degree from University of Basel, Switzerland in 1984. Then, in 1994, she received a PhD in genetics from the University of London. She is board certified in Internal Medicine and Hematology.

    Her clinical interests include acquired and inherited bone marrow failure, paroxysmal nocturnal hemoglobinuria, dyskeratosis congenita, Diamond Blackfan anemia, Shwachman Diamond syndrome and familial aplastic anemia and myelosdysplastic syndromes (MDS). Furthermore Dr. Bessler has a special interest in pediatric-adult transition for patients with bone marrow failure. She sees pediatric and adult patients and is interested in determining the adult manifestation and treatment of diseases that usually occurs in childhood as well as determining the early clinical signs in children with bone marrow failure conditions that usually only become obvious in the adult.

    Outside the clinic her laboratory research aims to define the molecular mechanisms that cause bone marrow failure and the factors that determine the clinical outcome and response to treatment. Bone marrow failure (BMF) is the inability of the bone marrow to produce sufficient blood cells. BMF may be brought about by a number of causes. These may be genetic (inherited bone marrow failure syndromes, IBMFS) or acquired. BMF may affect all, or only individual blood cell lineages. The aims of her research are a) to develop more specific tests or biomarkers that distinguish and diagnose individual forms of BMF, b) to identify the pathways that lead to BMF, c) to characterize the pathways responsible for late complications, such as the development of myelodysplastic syndrome (MDS) and leukemia, and finally d) to investigate specific and more targeted treatments for patients with BMF, allowing personalized therapy for patients with problems in blood cell production.

  • Education and Training

    Medical School

    MD - University of Zurich, Zurich Switzerland


    Clinical Pathology - Kantonspital St. Gallen, University of Basel, Basel, Switzerland
    Internal Medicine - Hospital Waid, Zurich University of Zurich, Zurich, Switzerland
    Internal Medicine - Hospital Triemli, Zurich, University of Zurich, Zurich, Swi


    Clinical Hematology - Department of Hematology, University Hospital of Zurich, Zurich, Switzerland
    Research fellow in Clinical Genetics - Institute for Clinical Genetics, University of Zurich, Zurich, Switzerland
    Research fellow in Hematology - Roya

    Additional Training

    Research Associate - Department of Human Genetics, Memorial Sloan-Kettering Cancer Center, New York, NY

    Board Certification

    Internal medicine

    Graduate Degree

    PhD in Genetics - University of London, London, UK

  • Titles and Academic Titles

    Attending Hematologist

    Director, Comprehensive Bone Marrow Failure Center

    Buck Family Endowed Chair in Hematology

    Professor of Pediatrics, Perelman School of Medicine at the University of Pennsylvania

  • Departments and Services
  • Publications



    Bessler M, Mason PJ, Link DC, Wilson DB. Inherited bone marrow failure syndromes. In: Orkin, SH Ginsburg, D, Nathan DG, Look, AT, Fisher, DE, Lux, SE, editors. Nathan’s and Oski’s hematology of infancy and childhood. 7th ed. Philadelphia: W.B. Saunders Co; 2008. p. 307-395.

    Du HY, Bessler M, Mason PJ. Telomerase mutations and premature ageing in humans. In: Rudolf KL, editor. Telomeres and telomerase in aging, disease, and cancer. New York: Springer; 2008. p. 77-107. 


    Bessler M, Kulkarni S, Jasinski M, Schaefer A, Keller P, Tremml G. Mice with blood cells deficient in GPI-linked proteins — the generation of a murine model to investigate the pathogenesis and pathophysiology of paroxysmal nocturnal hemoglobinuria (PNH). Proceedings of the International Symposium on paroxysmal nocturnal hemoglobinuria and related disorders. Tokyo (Japan): Springer-Verlag; 2003. p. 27-40. 


    Bessler M, Atkinson JP. Paroxysmal nocturnal hemoglobinuria (PNH). In: Stamatoyannopoulos, A. Nienhuis, P. Majerus, H. Varmus, editors. The molecular basis of blood diseases. 2nd ed. Philadelphia: W. B. Saunders Company; 2000. p. 564-79.

    Kinoshita T, Bessler M, Takeda J. Animal models of paroxysmal nocturnal hemoglobinuria. In: Paroxysmal nocturnal hemoglobinuria and the glycophosphoinositol-linked proteins. London: Academic Press; 2000. p. 139-55.



    Parikh S, Perdigones N, Paessler M, Greenbaum B, Tooke LS, Biegel JA, et al. Acquired copy number neutral loss of heterozygosity of chromosome 7 associated with clonal hematopoiesis in a patient with Shwachman-Diamond syndrome. Br J Haematol. 2012 Nov;159(4):480-2. doi: 10.1111/bjh.12032. Epub 2012 Aug 31. Cited in PubMed; PMID 22934832. No abstract available.

    Pesciotta EN, Sriswasdi S, Tang HY, Mason PJ, Bessler M, Speicher DW. A label-free proteome analysis strategy for identifying quantitative changes in erythrocyte membranes induced by red cell disorders. J Proteomics. E pub 2012 Aug 29. pii: S1874-3919(12)00627-6. doi: 10.1016/j.jprot.2012.08.010. Cited in PubMed; PMID 22954596. Read the abstract

    Parikh SV, Bessler M. Recent insights into inherited bone marrow failure syndromes. Curr Opin Pediatr. 2012 Feb;24(1):23-32. Cited in PubMed; PMID 22227778. Read the abstract


    Gu BW, Fan JM, Bessler M, Mason PJ. Accelerated hematopoietic stem cell aging in a mouse model of dyskeratosis congenita responds to antioxidant treatment. Aging Cell. 2011;10:338-348. Cited in PubMed; PMCID: PMC3238467. Read the article

    Ikeda K, Mason PJ, Bessler M. 3’UTR-truncated Hmga2 cDNA causes MPN-like hematopoiesis by conferring a clonal growth advantage at the level of HSC in mice. Blood. 2011 Jun 2;117(22):5860-9. Epub 2011 Apr 1. Cited in PubMed; PMID:21460244. 

    Mason PJ, Bessler M. Cytokinesis failure and attenuation: new findings in Fanconi anemia. J Clin Invest. 2011 Jan 4;121(1):27-30. doi: 10.1172/JCI45619. Epub 2010 Dec 22. Cited in PubMed; PMCID: PMC3007166. Read the article


    Bessler M, Wilson DB, Mason PJ. Dyskeratosis congenita. FEBS Lett. 2010 Sep 10;584(17):3831-8. Epub 2010 May 21. Cited in PubMed PMCID: PMC3238451; Read the article

    Ge J, Crosby SD, Heinz ME, Bessler M, Mason PJ. SnoRNA microarray analysis reveals changes in H/ACA and C/D RNA levels caused by dyskerin ablation in mouse liver. Biochem J. 2010 Jul 1;429(1):33-41. Cited in PubMed; PMID 20423331. Read the article

    Hill A, Rother RP, Wang X, Morris SM Jr, Quinn-Senger K, Kelly R, et al. Effects of eculizumab on haemolysis-associated nitric oxide depletion, dyspnoea, and measures of pulmonary hypertension in patients with paroxysmal nocturnal haemoglobinuria. Br J Haematol. 2010 May;149(3):414-25. Epub 2010 Mar 8. Cited in PubMed; PMID 20423331. Read the abstract

    Ge J, Rudnick DA, He J, Crimmins DL, Ladenson JH, Bessler M, et al. Dyskerin ablation in mouse liver inhibits ribosomal RNA processing and cell division. Mol Cell Biol. 2010 Jan;30(2):413-22. Epub 2009 Nov 16. Cited in PubMed; PMID 19917719. Read the article

    McDonald S, Wilson DB, Pumbo E, Kulkarni S, Mason PJ, Else T, et al. Acquired monosomy 7 myelodysplastic syndrome in a child with clinical features suggestive of dyskeratosis congenita and IMAGe association. Pediatr Blood Cancer. 2010 Jan;54(1):154-7. Cited in PubMed; PMID 19760774. Read the abstract

    Posters and Presentations


    Bessler M. From pediatric care to adult care: helping young bone marrow failure patients with making a successful transition [webinar]. Aplastic Anemia and MDS International Foundation; 2012 Sep.


    Bessler M. Paroxysmal nocturnal hemoglobinuria: from bench to bedside and back to the bench [presentation]. Pediatric Grand Rounds, New York Presbyterian Hospital-Weill Cornell Medical Center: 2011 Apr; New York, NY

    Bessler M. Management of adult Shwachman-Diamond syndrome patients [presentation]. Sixth International Congress on Shwachman-Diamond Syndrome; 2011 Jun; New York Academy of Sciences, New York, NY.


    Bessler M. AA&MDSIF National Patient & Family Conference; 2010 Jul; Washington DC.

    Bessler M. Pediatric adult transition for bone marrow failure patients. Camp Sunshine for Shwachman Diamond Syndrome; 2010 Jul; Portland ME.
    Bessler M. Camp Sunshine for families with Dyskeratosis Congenita; 2010 Sep; Portland, ME.

    Bessler M. Department of Pediatrics Hematology/Oncology Seminar Series. Dana-Farber Cancer Institute/Children’s Hospital Boston Cancer Center; 2010 Sep; Boston, MA.

    Bessler M. Opportunities and challenges in the laboratory and translational research [presentation]. Clinical American Society of Hematology; 2010 Dec 4-7; Orlando, FL.