Myelodysplastic neoplasms
MDS with low blasts and isolated 5q deletion
Also called Myelodysplastic neoplasm with low blasts and isolated 5q deletion
If you or someone you love has just heard this diagnosis, start here. This guide explains what the condition is, how it is usually treated and whether a transplant plays any part.
MDS with low blasts and a 5q deletion is a marrow cancer with loss of genetic material from chromosome 5. Anemia is often the main problem, and many people start with blood-supporting treatment rather than a donor transplant.
Other names and abbreviations
MDS-del(5q), del5q MDS, 5q− syndrome, myelodysplastic syndrome, MDS, MDS with isolated del(5q), 5q-minus syndrome (historical narrower phenotype)
In short
- This type of MDS is a marrow cancer in which part of chromosome 5 is missing. Few cells are immature blasts, and anemia is often the main problem.
- People with mild blood-count problems may be watched. Others may get red-cell transfusions or, for some, lenalidomide to reduce transfusion needs.
- Transplant is usually not the first step. But a donor transplant may be used if blood counts stay very low despite treatment, higher-risk gene changes appear or the disease gets worse.
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Underlined words open a short explanation. See all terms
Where transplant fits
TransplantA treatment that gives a patient healthy blood-forming stem cells through a vein. The cells travel to the bone marrow and replace faulty marrow or marrow damaged by treatment. They can come from the patient or a donor. is generally deferred in well-controlled lower-risk disease. Allogeneic transplantationComing from another person. In an allogeneic, or donor, transplant, the stem cells come from a relative or an unrelated volunteer whose cells are a close enough match to the patient's. may become appropriate for severe refractoryDescribes a disease that does not respond to treatment. It may resist treatment from the start, or treatment may stop working along the way. blood-count problems, adverse features or progression, using a suitable family or unrelated donor or alternative graftThe blood-forming stem cells given to a patient in a transplant. In a donor transplant, the graft comes from the donor's bone marrow or blood, or from donated cord blood..
Treatment depends on the exact diagnosis, disease stage, prior treatment and the person’s health.
Key facts
- Who it affects
- This subtype mainly affects older adults and is more frequently described in women.
- How common
- About 5 or 6 in every 100 people with MDS (5.5%)134 of 2,454 people with MDS in an international research dataset (Bernard et al., shared on cBioPortal), reclassified under the 2022 WHO system; published 2025. A research cohort, not a population count. Source: How common
- Cells used in a transplant
- Donated blood-forming cells for allogeneic transplantation. Marrow, peripheral blood or cord blood and donor type are selected for the patient and transplant approach.
- Where a donor fits
- Limited transplant role
The condition
What it is
Myelodysplastic neoplasmsA group of cancers in which the bone marrow does not make enough healthy blood cells and abnormal cells appear in the blood or marrow. Also called myelodysplastic syndromes (MDS). Sometimes they turn into acute myeloid leukemia., also called myelodysplastic syndromes (MDS), are cancers of blood-forming stem cellsYoung cells that can grow into every type of blood cell: red cells that carry oxygen, white cells that fight infection and platelets that help blood clot. They are found in the bone marrow and the bloodstream.. Abnormal development means the marrowThe soft, spongy tissue in the center of most bones. Red bone marrow holds the blood-forming stem cells that make red blood cells, white blood cells and platelets. does not reliably produce enough working blood cells. MDS can cause serious problems without ever progressing to acute myeloidHaving to do with the bone marrow, or with certain blood-forming cells made there. Also called myelogenous. Acute myeloid leukemia (AML) is a fast-growing cancer that starts in these cells. leukemia (AML).
This subtype is defined by a deletion on the long arm of chromosome 5 together with specific marrow and genetic criteria. “Low blastsYoung blood cells that have not finished developing. In leukemia and some related diseases, abnormal blasts build up in the marrow and blood and leave less room for healthy blood cells. Doctors count blasts to help identify the disease.” describes a small proportion of immature cells. The name does not mean that every patient has the same severity or that every chromosome 5 abnormality belongs to this subtype.
Marked as affected: blood stem cells and red blood cells.
- Blood stem cell, Affected, In the bone marrow
- Myeloid line
- Red blood cells, Affected
- Platelets
- Granulocytes
- Monocytes
- Lymphoid line
- B cells
- Plasma cells, Develop from B cells
- T cells
- NK cells, Natural killer cells
- Myeloid line
What causes it
MDS usually develops through acquired genetic changes in blood-forming cells, and the underlying cause is often unknown. Age, previous chemotherapy or radiation, smoking and some chemical exposures can increase risk.
Inherited predisposition can contribute in a minority of patients. Personal and family history may prompt genetic evaluation, which can also affect the suitability of related donors. MDS is not contagious.
Symptoms and effects
Anemia can cause fatigue, breathlessness or difficulty with ordinary activities. Low neutrophilsA type of white blood cell that is one of the first to respond to germs such as bacteria. Low neutrophil levels raise the risk of serious infection. increase infection risk, and low platelets can cause bruising or bleeding. Some people first learn about MDS through a routine blood test.
Blood counts, marrow findings and molecular tests help track the disease. The subtype name and the overall risk score answer different questions: prognosis depends on the combination of genetic findings, blast count and blood-cell shortages, not a single label.
Some additional genetic findings, especially TP53 abnormalities, can change prognosis and classification. Monitoring therefore includes more than whether the 5q deletion is still present.
Diagnosis and treatment
How MDS with a 5q deletion is diagnosed
This type of MDS often first shows up on a routine blood test. The usual clue is anemia, a low red blood cell count. The first tests are a complete blood count (CBC) and a blood smear. In a smear, blood cells are checked under a microscope. Blood tests for vitamin B12 and folate help rule out other causes of anemia.
A hematologist (blood doctor) confirms MDS with a bone marrow aspiration and biopsy, usually taken from the hip bone or breastbone. The pathologist counts blasts, the immature cells. For this subtype, blasts must be under 5 in every 100 marrow cells and under 2 in every 100 white cells in the blood. Chromosome tests (a karyotype, and sometimes FISH) find the missing piece of the long arm of chromosome 5, called 5q. The 5q loss can be the only chromosome change. It can also come with one other change, as long as that change is not a loss of chromosome 7 or part of its long arm (7q).
Gene testing, often with a panel test called next-generation sequencing, looks for changes such as TP53. If both copies of TP53 are damaged, the disease is placed in a different subtype. The team then combines blood counts, blasts and genetic results into a risk score, such as the IPSS-R or the newer IPSS-M.
The subtype name describes the marrow. The risk score and gene results say more about what to expect.
How it is treated
People whose anemia or other blood-count problems are mild may be monitored. Treatment can include red-cell transfusions and medicines that support red-cell production.
Lenalidomide can reduce transfusion needs in appropriately selected people with lower-risk, transfusion-dependent del(5q) MDS. It also can worsen blood counts, particularly early in treatment, so dosing and follow-up require close supervision. The response and other genetic findings matter when deciding how long to continue it.
Transplant is usually deferred when lower-risk disease is controlled with less intensive measures. Allogeneic transplantation may become appropriate with severe refractory blood-count problems, adverse genetic features or progression. “Lower risk” does not mean that a person can never benefit from transplant.
Kinds of treatment described for MDS with low blasts and isolated 5q deletion: watching and regular checks, supportive care, medicines (for some people) and a donor stem cell transplant (for some people).
After diagnosis, the options described here
Watching and regular checks
People whose anemia or other blood-count problems are mild may be watched.
Supportive care
Red-cell transfusions and medicines that support red-cell production can treat anemia.
Medicines, For some people
Lenalidomide, a pill, can reduce the need for transfusions.
Donor stem cell transplant, For some people
A donor transplant can cure MDS for some people, but it is usually not a first treatment and is discussed if the disease stops responding.
These are the kinds of treatment this page describes, not a plan. Which ones fit, in what order and whether they are combined differs from person to person.
When transplant specialists are usually consulted
Transplant is not usually part of first treatment for this subtype. NMDP's consultation timing guidelines recommend HLA typingA lab test that finds a person's tissue type (HLA markers). It starts with a blood draw or a cheek swab. Doctors compare a patient's results with those of relatives, registry donors and cord blood units. and a transplant consultation for people with MDS who have certain features. These include needing regular transfusions, low blood counts that do not improve with treatment, higher-risk chromosome or gene changes, or treatment that has stopped working.
Read the guidanceDaily life and the donor’s role
Living with the condition and treatment
Repeated blood tests, clinic visits and sometimes marrow samples are part of care. Some people need regular transfusions or medicines to support blood production. The practical burden depends on the degree of anemia, infection risk, treatment schedule and other health conditions.
If transplant is considered, discussions include the chance of disease control, treatment-related risks, recovery support and personal goals. A donor search can take place while these decisions and other treatment continue.
The role of a blood stem cell donor
Most people with stable lower-risk del(5q) disease do not need an immediate registry donor. Donor evaluation becomes relevant when the team is considering allogeneic transplantation.
When allogeneic transplantation is selected, the graft comes from another person. A matched relative, unrelated registry donor or an appropriate alternative donor may be suitable. HLA compatibilityMarkers on most cells that make up a person's tissue type. Doctors test a patient's and donor's HLA to see how well they match. The more markers they share, the better the chance the body accepts the donor's cells., donor age and availability, patient health and the transplant approach all matter; no donor category is best for every person.
Looking ahead
Looking ahead
Outlook for MDS with a 5q deletion
MDS with a 5q deletion is linked to longer survival than many other kinds of MDS. Anemia is often the main problem. Most people fall into the lower-risk groups of standard risk scores. Many respond to lenalidomide, a pill that can end the need for red cell transfusionsPutting blood, or parts of blood such as red cells or platelets, into a person's bloodstream through a vein. Some people with blood disorders need regular transfusions. for a time.
Outlook still varies widely. A large 2026 international study linked a harder course to several features. These were age 70 or older, male sex, low hemoglobin (10 g/dL or less) and low plateletsTiny pieces of cells in the blood that help form clots to slow or stop bleeding. They are made in the bone marrow. Too few platelets can cause easy bruising and bleeding. (100 or lower). Genetic factors counted too: one extra chromosome change, two or more gene mutations, an SF3B1 mutation, and high-risk TP53 changes. Standard risk scores did not sort risk well in this subtype, so the authors proposed a score made for it.
A donor stem cell transplant can cure MDS in some people. For this subtype, it is usually not a first treatment.
About these numbers. Each one says which group of people it comes from, and the place and years where the source gives them. It describes what happened across that group, not what will happen to any one person. And a figure measured among people who had a transplant is not the same as the number of people who need one.
- About 6 years (73.8 months)Median survival (half of people lived longer)
People with MDS with isolated del(5q) under the 2017 WHO definition (including some with multi-hit TP53), diagnosed 1997–2022 at 19 institutions in several countries; 682 people, survival data for 539; median age 74; published 2026
Read the source: Median survival (half of people lived longer) - 23% (115 of 507 people with follow-up data)MDS turned into AML within 5 years
Same international cohort of people with MDS with isolated del(5q), diagnosed 1997–2022
Read the source: MDS turned into AML within 5 years - 67% (99 of 148)Stopped needing red cell transfusions on lenalidomide
148 people with lower-risk, transfusion-dependent MDS with a chromosome 5 deletion (alone or with other changes) in the phase 2 trial that led to U.S. approval (List et al., 2006)
Read the source: Stopped needing red cell transfusions on lenalidomide
These numbers describe groups of people. They cannot tell any one person how long they will live or how treatment will go.
Common questions
What is 5q minus syndrome?
"5q minus syndrome" (5q− syndrome) is an older term. It first described anemia with normal or high platelet counts in people whose marrow cells were missing part of the long arm (q) of chromosome 5. The closest current name, from the World Health Organization's 2022 system, is MDS with low blasts and isolated 5q deletion. It is more common in women. In a large international study, 73 of every 100 patients were women, and the median age at diagnosis was 74.
What is the life expectancy with MDS with a 5q deletion?
No number can predict one person's course. The outlook section on this page gives typical survival from a 2026 study of 682 people. In that study, the course was harder for people who were 70 or older, were male or had lower blood counts. It was also harder with an extra chromosome change or certain gene changes, such as TP53 or SF3B1. This is why care teams use risk scores and repeat tests over time.
How well does lenalidomide work for 5q deletion MDS?
Lenalidomide is a pill approved for lower-risk MDS with a chromosome 5 deletion when a person needs regular red cell transfusions. In the trial that led to approval, most people stopped needing transfusions. The outlook section on this page gives the figure. The median time to respond was about 4 to 5 weeks. It often lowers neutrophil and platelet counts, so blood counts are checked often. If it stops working, other options can include other anemia medicines or, for some people, a donor transplant.
Can MDS with a 5q deletion turn into leukemia?
It can, though it often takes years. In a large international study, about 23 of every 100 people with follow-up data developed acute myeloid leukemia (AML) within 5 years. Among those who did, the median time was 32 months. Earlier studies linked a higher risk to needing transfusions, low platelet counts and more blasts. Gene changes such as TP53 also matter. This is why care teams keep checking blood counts.
Is MDS with a 5q deletion inherited?
Usually not. MDS starts when a blood-forming stem cell picks up a genetic change during a person's life. The 5q deletion is found in the abnormal marrow cells. It is not passed down from parents. Known risk factors for MDS include past chemotherapy or radiation for cancer, tobacco smoke, some chemicals such as benzene and pesticides, and heavy metals such as lead or mercury.
Can MDS with a 5q deletion be cured?
A donor stem cell transplant can cure MDS for some people. It is usually not a first treatment for this subtype, which often moves slowly. Lenalidomide and other treatments aim to control the disease, reduce transfusions and ease symptoms. A transplant is usually discussed if the disease stops responding, blood counts stay very low, or higher-risk changes appear.
For your next appointment
MDS with low blasts and isolated 5q deletion
From the Jada Bascom Foundation disease library, jadabascomfoundation.org. Printed .
Questions to bring to your care team
- Is the 5q deletion the only chromosome change, and did gene testing find TP53, SF3B1 or other mutations?
- What is my risk group, and which features of my disease matter most for my outlook?
- If I start lenalidomide, how often will my blood counts be checked, and what comes next if it stops working?
- Will my marrow or gene tests be repeated over time, and what changes would you look for?
- What is the exact name of the diagnosis or subtype, and what does it mean for treatment?
- What is the goal of each treatment you are suggesting?
- What would make a transplant worth considering later on?
- Are there clinical trials that might fit?
- Where can our family find support during treatment?
A one-page list to take to the next appointment, with room for notes.
Supporting someone with a diagnosisSupport for patients and families
These independent organizations offer information and support. JBF is not affiliated with them.
- MDS Foundation A global nonprofit offering MDS education, patient guides, patient forums and ways to connect with experts and other patients.Worldwide
- Aplastic Anemia and MDS International Foundation (AAMDSIF) Offers patient guides, a helpline, virtual support groups and a peer support network for people with MDS and related bone marrow diseases.United States
- MDS UK Patient Support Group A UK charity offering free membership, trusted information, online support meetings and one-to-one help for people with MDS or CMML and carers.United Kingdom
Sources and further reading
- Myelodysplastic Syndromes Treatment (PDQ), Health Professional Version
NCI, Accessed 2026-09-05 - Myelodysplastic Neoplasms/Syndromes (MDS)
EBMT Handbook / NCBI Bookshelf, Accessed 2026-09-05 - WHO fifth-edition classification: Myeloid and Histiocytic/Dendritic Neoplasms
WHO classification authors / Leukemia, Accessed 2026-09-05 - Indications for haematopoietic cell transplantation and CAR-T: 2025 EBMT practice recommendations
EBMT / Bone Marrow Transplantation, Accessed 2026-09-05 - Stem Cell and Bone Marrow Transplants for Cancer
NCI, Accessed 2026-09-05 - Donor and cord blood unit selection guidelines
NMDP / CIBMTR, Accessed 2026-09-05 - Myelodysplastic Syndromes Treatment (PDQ), Patient Version
National Cancer Institute (PDQ), Updated 2024-10-04; accessed 2026-09-26 - Myelodysplastic Syndromes: 2026 Update on Diagnosis, Risk-Stratification and Management
American Journal of Hematology (Garcia-Manero G), 2026 - Comprehensive analysis of prognostic factors in myelodysplastic syndromes with isolated deletion of chromosome 5q
Blood Advances (Montoro MJ et al.), 2026 - Clinical and Biological Insights into Myelodysplastic Neoplasms Associated with Deletions of Chromosome 5q Region
Hematology Reports (Testa U et al.), 2025 - Reclassification of Myelodysplastic Neoplasms According to the 2022 World Health Organization Classification and the 2022 International Consensus Classification Using Open-Source Data: Focus on SF3B1- and TP53-Mutated Myelodysplastic Neoplasms
Annals of Laboratory Medicine, 2025 - Consultation timing guidelines: myelodysplastic syndromes (MDS)
NMDP, Accessed 2026-09-26
This information explains a condition and its treatments. It cannot diagnose an illness or recommend treatment for an individual. Your care team can explain how the evidence applies to you. Written and source-checked by the Jada Bascom Foundation. Each page lists the published sources it draws on.
Ways to help
Help another family understand.
Most people with MDS with low blasts and isolated 5q deletion are treated without a registry donor. A clear explanation can help the next family who hears this diagnosis, and many people with other blood cancers and blood disorders need a donor who is a stranger.
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More in the library
Keep learning
Interactive storyWhy matching is hard: leukemiaHow leukemia affects blood production, when a donor transplant may help, and how inherited HLA markers shape the search for a suitable donor.Begin the storyPart of 2 diagnosis guides, each explaining how its subtypes fit together: Myelodysplastic syndromes (MDS) and Types of blood cancer.
