Kleber Yotsumoto Fertrin, MD, PhD

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Yotsumoto Fertrin
Kleber Yotsumoto Fertrin, MD, PhD

Kleber Yotsumoto Fertrin, MD, PhD

  • Director, Sickle Cell Disease and Iron Overload Program, Fred Hutch
  • Assistant Professor, Division of Hematology and Oncology, University of Washington School of Medicine


“I believe it is my responsibility to provide patients with access to modern medical advances while preserving personalized care that respects each patient’s needs and beliefs.”
— Dr. Yotsumoto Fertrin

What is an important factor in patient care?

Personalized care is very important. Each patient I see is different and has different needs. Being an effective listener and building trust helps me address those varying needs. In the future, I hope we can apply modern technology to achieve not only personalized diagnosis and treatment of hematologic diseases, but personalized prevention of diseases as well.

Why do you work in health care?

I decided to be a doctor because I didn’t want to be around machines all the time. For a long time, I envisioned being an engineer because I was very good at math, but I wanted to be able to have daily interactions with people. As a teenager, I decided to work in health care because I found myself very interested in genetics research. Here at Fred Hutch, I have a nice combination of caring for my patients in clinic while also conducting research.

Provider Background

Area of Clinical Practice
Hematologic malignancies, non-malignant hematology, sickle cell disease

Iron Overload
In Brazil, where I’m originally from, thalassemia and sickle cell disease are public health problems and are managed almost entirely by specialized public hematology centers — all the way from diagnosis to treatment with transfusion and bone marrow transplantation. I first studied hemoglobin disorders as an undergraduate; this life-changing opportunity eventually brought me closer to patients, but also piqued my interest in research to try to help solve the issues I faced on a daily basis in the clinic. Recently, a complication that has particularly caught my eye is iron overload — specifically, trying to understand its clinical heterogeneity across different anemias and working toward better management of the condition.

Hemolytic Anemias
Benign hematology chose me. I happened to join a professor’s lab when I was an undergrad, and he worked with hemolytic anemias, especially the genetic ones. From that point on, I fell in love with the field. Prior to joining the team at Fred Hutch, I was a professor of hematology at the University of Campinas in Brazil. I have been involved in translational and clinical research involving red cell disorders and its complications since my medical school years.

Diseases Treated

Autoimmune Diseases

Blood Disorders

Essential Thrombocytosis

Hemolytic Anemias

Hereditary Spherocytosis

Idiopathic Thrombocytopenic Purpura

Iron Deficiency Anemia

Iron Overload

Monoclonal Gammopathy


Paroxysmal Nocturnal Hemoglobinuria

Polycythemia Vera

Severe Congenital Neutropenia

Sickle Cell Disease




Education, Experience and Certifications

Medical Degree
University of Campinas

University of Campinas, Internal Medicine

University of Campinas, Clinical Hematology and Transfusion Medicine; National Heart, Lung, and Blood Institute, Bethesda

PhD, University of Campinas; Teaching Appointment, University of Campinas

Clinical Trials

We make promising new treatments available to you through studies called clinical trials led by Fred Hutch physicians. Many of these trials at Fred Hutch have led to FDA-approved treatments and have improved standards of care globally. Together, you and your physician can decide if a study is right for you. 

View Clinical Trials


Many of our Fred Hutch physicians conduct ongoing research to improve standards of patient care. Their work is evaluated by other physicians and selected for publication to the United States National Library of Medicine, the largest medical library in the world. See scientific papers this Fred Hutch physician has written. 

View Dr. Yotsumoto Fertrin's Publications

Your Care Team

At Fred Hutch, you receive care from a team of providers with extensive experience in your disease. Your team includes physicians, a patient care coordinator, a registered nurse, an advanced practice provider and others, based on your needs. You also have access to experts like registered dietitians, social workers, acupuncturists, psychiatrists and more who specialize in supporting people with cancer or blood disorders. 


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For the Media

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Email media@fredhutch.org or call 206.667.2210