Understand the condition.
See where a donor fits.

Cancers of blood-forming cells. The affected cell type and the pace of disease shape treatment. Explore leukemias

• Acute myeloid leukemia (AML)

  Acute myeloid leukemia (AML) is a fast-growing cancer of blood-forming cells. Treatment is tailored to the leukemia’s genetic features, response to therapy and the person’s health; some people benefit from a donor stem cell transplant.

  Donor transplant option

• Acute promyelocytic leukemia (APL)

  Acute promyelocytic leukemia (APL) is a distinct form of AML, usually driven by a PML::RARA gene fusion. It can cause dangerous bleeding, but prompt treatment with differentiation medicines allows many people to recover without a stem cell transplant.

  Limited transplant role

• Adult T-cell leukemia/lymphoma (ATLL)

  Adult T-cell leukemia/lymphoma (ATLL) is a cancer of mature T cells associated with long-standing HTLV-1 infection. Treatment differs by subtype; a donor transplant is an important potentially curative option for eligible people with aggressive disease.

  Donor transplant option

• Aggressive NK-cell leukemia (ANKL)

  Aggressive NK-cell leukemia (ANKL) is a very rare, fast-growing cancer of mature natural killer (NK) cells in the blood, bone marrow, liver and spleen. It is usually linked to Epstein-Barr virus and often causes fever, liver problems and severe inflammation.

  Donor transplant option

• B-cell acute lymphoblastic leukemia (B-ALL)

  B-cell acute lymphoblastic leukemia (B-ALL) is a fast-growing cancer of immature B lymphocytes. Treatment often controls it without transplant, while donor transplantation and selected immunotherapies are important for some higher-risk or relapsed cases.

  Donor transplant option

• B/myeloid mixed-phenotype acute leukemia (MPAL)

  B/myeloid mixed-phenotype acute leukemia (MPAL) is an acute leukemia with defining features of both B-lymphoid and myeloid lineages. Expert review of cell markers and genetics is needed because this is different from ordinary B-ALL or AML with an occasional extra marker.

  Donor transplant option

• Chronic lymphocytic leukemia (CLL/SLL)

  Chronic lymphocytic leukemia and small lymphocytic lymphoma (CLL/SLL) are two presentations of the same mature B-cell cancer. Many people initially need monitoring; targeted medicines are the usual treatment, and donor transplantation is reserved for selected difficult-to-treat disease.

  Limited transplant role

• Chronic myeloid leukemia (CML)

  Chronic myeloid leukemia (CML) is a blood cancer driven by the BCR::ABL1 fusion. Most people start with a targeted medicine, while a donor stem cell transplant remains an option for resistant disease or progression.

  Limited transplant role

• Hairy cell leukemia (HCL)

  Hairy cell leukemia (HCL) is a rare, slow-growing cancer of B cells that builds up in the bone marrow and spleen and lowers normal blood counts. Nearly all classic cases carry a BRAF V600E change in the leukemia cells.

  Limited transplant role

• Philadelphia-positive acute lymphoblastic leukemia (Ph+ ALL)

  Philadelphia chromosome-positive ALL is usually a B-lineage acute leukemia containing the BCR::ABL1 fusion. The fusion makes an overactive growth-signaling enzyme, so treatment includes medicines directed at that target.

  Donor transplant option

• T-cell acute lymphoblastic leukemia (T-ALL)

  T-cell acute lymphoblastic leukemia (T-ALL) is a fast-growing cancer of immature T cells. Treatment uses an ALL regimen; donor transplantation is considered when the response or disease features indicate a substantial risk of relapse.

  Donor transplant option

• T-cell prolymphocytic leukemia (T-PLL)

  T-cell prolymphocytic leukemia (T-PLL) is a rare, often aggressive cancer of mature T cells. It can produce a very high lymphocyte count, enlarged organs, skin involvement and systemic symptoms.

  Donor transplant option

• Therapy-related AML and MDS (t-AML, t-MDS)

  Therapy-related AML and MDS are blood cancers that can develop months or years after chemotherapy or radiation for an earlier illness, usually another cancer. The WHO calls this group myeloid neoplasms post cytotoxic therapy. It is treated much like other AML and MDS, and it is often harder to treat.

  Donor transplant option

Cancers of lymphocytes, a type of white blood cell. There are many subtypes with different treatments. Explore lymphomas

• ALK-negative anaplastic large cell lymphoma (ALCL)

  ALK-negative anaplastic large cell lymphoma (ALCL) is a CD30-positive T-cell lymphoma without an ALK rearrangement. Treatment commonly uses drug combinations, with autologous or donor transplantation considered in selected situations.

  Usually the person’s own cells

• ALK-positive anaplastic large cell lymphoma (ALCL)

  ALK-positive anaplastic large cell lymphoma (ALCL) is a CD30-positive T-cell lymphoma driven by an ALK rearrangement. Many patients respond well to initial drug treatment; transplantation is mainly considered for selected higher-risk or relapsed disease.

  Limited transplant role

• Angioimmunoblastic T-cell lymphoma (AITL)

  The World Health Organization’s 2022 classification calls angioimmunoblastic T-cell lymphoma “nodal T-follicular helper cell lymphoma, angioimmunoblastic-type.” It can disrupt immune function as well as cause lymphoma growth, and treatment may include selected stem cell transplant approaches.

  Usually the person’s own cells

• Burkitt lymphoma

  Burkitt lymphoma is a rapidly growing mature B-cell cancer associated with abnormal MYC activity. Prompt, specialized drug treatment can cure many patients; stem cell transplantation is not the usual first-line treatment.

  Limited transplant role

• Chronic active Epstein-Barr virus disease (CAEBV)

  Chronic active Epstein–Barr virus disease (CAEBV) is a rare, often life-threatening illness in which Epstein–Barr virus (EBV), the virus behind mono, stays active in T cells or natural killer (NK) cells. The infected cells multiply and inflame organs, and the illness can lead to HLH or to lymphoma.

  Donor transplant option

• Classic Hodgkin lymphoma

  Classic Hodgkin lymphoma is a B-cell cancer identified by characteristic Hodgkin and Reed–Sternberg cells. Many people are cured with initial drug treatment, sometimes with radiotherapy; transplant is mainly used when the lymphoma returns or resists treatment.

  Usually the person’s own cells

• Diffuse large B-cell lymphoma (DLBCL)

  Diffuse large B-cell lymphoma (DLBCL) is an aggressive cancer of mature B cells. Many people are cured with initial treatment. At relapse, the choice among CAR-T therapy, autologous transplantation and other treatments depends on timing and response.

  Cell or gene therapy options

• Double-hit lymphoma (MYC and BCL2 rearranged)

  Double-hit lymphoma is a fast-growing B-cell lymphoma in which the MYC and BCL2 genes are both rearranged. The World Health Organization now calls it diffuse large B-cell lymphoma/high-grade B-cell lymphoma with MYC and BCL2 rearrangements. It is found by a lab test on the biopsy and is different from “double-expressor” lymphoma.

  Cell or gene therapy options

• Extranodal NK/T-cell lymphoma (ENKTL)

  Extranodal NK/T-cell lymphoma is an Epstein-Barr virus-associated lymphoma that often affects the nose and nearby tissues. Treatment depends strongly on its extent; selected advanced or relapsed cases may benefit from a donor transplant.

  Donor transplant option

• Follicular lymphoma

  Follicular lymphoma is usually a slow-growing B-cell cancer. Treatment ranges from monitoring to radiotherapy, medicines and cellular therapy; transplantation is considered for selected higher-risk or relapsed disease.

  Cell or gene therapy options

• Hepatosplenic T-cell lymphoma (HSTCL)

  Hepatosplenic T-cell lymphoma is a rare, aggressive lymphoma that mainly involves the liver, spleen and bone marrow. Early specialist treatment and donor-transplant assessment are important because ordinary lymphoma chemotherapy alone often gives short-lived control.

  Donor transplant option

• Mantle cell lymphoma (MCL)

  Mantle cell lymphoma (MCL) is a mature B-cell cancer with a variable pace. Targeted medicines and immunotherapy are changing treatment, including when autologous transplant is useful; donor transplantation is reserved for selected situations.

  Cell or gene therapy options

• Marginal zone lymphoma (MZL)

  Marginal zone lymphoma (MZL) is a group of slow-growing B-cell lymphomas. The main types are extranodal (MALT) lymphoma, which often starts in the stomach or other organs, nodal MZL and splenic MZL.

  Limited transplant role

• Mycosis fungoides

  Mycosis fungoides is a T-cell lymphoma that usually begins in the skin. Early disease is often treated with skin-directed therapies; a donor stem cell transplant is an option for selected advanced or difficult-to-treat cases.

  Limited transplant role

• Nodular lymphocyte-predominant Hodgkin lymphoma (NLPHL)

  Nodular lymphocyte-predominant Hodgkin lymphoma (NLPHL) is a rare, usually slow-growing B-cell lymphoma that differs from classic Hodgkin lymphoma. Its large LP (“popcorn”) cells carry B-cell markers such as CD20. Most people are diagnosed at an early stage and do very well.

  Limited transplant role

• Peripheral T-cell lymphoma (PTCL-NOS)

  Peripheral T-cell lymphoma, not otherwise specified (PTCL-NOS), is a cancer of mature T cells that does not fit another defined subtype. Treatment often uses combination chemotherapy; selected patients may receive an autologous or donor transplant.

  Usually the person’s own cells

• Primary CNS lymphoma (PCNSL)

  Primary central nervous system lymphoma starts in the brain, spinal cord, eyes or nearby coverings without lymphoma elsewhere at diagnosis. Treatment must reach these sites; eligible patients may receive high-dose chemotherapy followed by their own stem cells.

  Usually the person’s own cells

• Primary mediastinal large B-cell lymphoma (PMBCL)

  Primary mediastinal large B-cell lymphoma (PMBCL) is an aggressive lymphoma that usually begins in the chest between the lungs. Initial treatment can be curative; transplantation and CAR-T therapy are mainly considered for resistant or relapsed disease.

  Cell or gene therapy options

• Richter transformation (Richter syndrome)

  Richter transformation is when chronic lymphocytic leukemia (CLL) or small lymphocytic lymphoma (SLL) turns into a fast-growing lymphoma, most often diffuse large B-cell lymphoma and less often Hodgkin lymphoma. It needs prompt treatment, and doctors check whether the new lymphoma grew from the same cells as the CLL.

  Donor transplant option

• Sézary syndrome

  Sézary syndrome is a mature T-cell lymphoma involving the blood and usually causing widespread inflamed, itchy skin. Systemic treatment is central; a donor stem cell transplant can offer lasting remission for selected eligible patients.

  Donor transplant option

• Waldenström macroglobulinemia

  Waldenström macroglobulinemia is a lymphoplasmacytic lymphoma that produces an IgM antibody protein. Some people need only monitoring; medicines are the usual treatment, with transplantation reserved for selected relapsed disease.

  Limited transplant role

Disorders in which abnormal blood formation leads to low blood counts. Treatment depends on the disease’s risk and its effects. Explore myelodysplastic neoplasms

• Atypical chronic myeloid leukemia (aCML)

  Atypical chronic myeloid leukemia (aCML) is a rare blood cancer with features of both myelodysplastic syndromes and myeloproliferative neoplasms. The marrow makes too many abnormal neutrophil-line cells. It lacks the BCR::ABL1 gene that defines CML, and the WHO now calls it MDS/MPN with neutrophilia.

  Donor transplant option

• Chronic myelomonocytic leukemia (CMML)

  Chronic myelomonocytic leukemia (CMML) is a blood cancer with both abnormal blood-cell development and excess monocytes. Treatment depends on its pace and risk; a donor stem cell transplant is the established option with curative potential for eligible people.

  Donor transplant option

• MDS with biallelic TP53 inactivation (multi-hit TP53)

  MDS with biallelic TP53 inactivation is a high-risk myelodysplastic neoplasm in which both copies of an important tumor-suppressor gene are affected. Donor transplantation may offer a chance of lasting disease control, but relapse remains a major concern.

  Donor transplant option

• MDS with increased blasts (MDS-IB)

  MDS with increased blasts is a myelodysplastic neoplasm with a raised proportion of immature blood cells. It often follows a higher-risk treatment pathway, including consideration of a donor stem cell transplant for eligible people.

  Donor transplant option

• MDS with low blasts and isolated 5q deletion

  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.

  Limited transplant role

• MDS with low blasts and SF3B1 mutation

  MDS with low blasts and an SF3B1 mutation is a genetically defined marrow cancer that often causes anemia. Many people receive monitoring and treatment to improve blood production; donor transplantation is considered only in selected circumstances.

  Limited transplant role

Conditions in which the marrow makes too many blood cells. Some involve marrow scarring or a risk of progression. Explore myeloproliferative neoplasms

• Advanced systemic mastocytosis (AdvSM)

  Advanced systemic mastocytosis is a rare blood cancer in which abnormal mast cells, usually carrying the KIT D816V gene change, build up in the bone marrow and other organs and impair how they work. It includes aggressive systemic mastocytosis, systemic mastocytosis with an associated hematologic neoplasm, and mast cell leukemia.

  Limited transplant role

• Chronic neutrophilic leukemia (CNL)

  Chronic neutrophilic leukemia (CNL) is a rare blood cancer in which the marrow makes too many mature neutrophils. It commonly involves a CSF3R gene alteration and must be distinguished from infection-related neutrophilia and other myeloid cancers.

  Donor transplant option

• Essential thrombocythemia (ET)

  Essential thrombocythemia (ET) is a slow-growing blood cancer, one of the myeloproliferative neoplasms, in which the bone marrow makes too many platelets. Most people have a JAK2, CALR or MPL gene change. The main risks are blood clots and bleeding, and over many years a small number of people see ET change into myelofibrosis or, less often, acute myeloid leukemia.

  Not treated with transplant

• Juvenile myelomonocytic leukemia (JMML)

  Juvenile myelomonocytic leukemia (JMML) is a rare blood cancer of early childhood driven by abnormal RAS-pathway signaling. Most children need a donor stem cell transplant, while a small genetically defined group may follow a different course.

  Donor transplant option

• Myeloid/lymphoid neoplasm with FGFR1 rearrangement

  Myeloid/lymphoid neoplasm with FGFR1 rearrangement is a rare, aggressive blood cancer caused by a broken and rejoined FGFR1 gene on chromosome 8 (8p11). It can appear as a myeloproliferative neoplasm, an acute leukemia or a lymphoma, often with extra eosinophils. It used to be called 8p11 myeloproliferative syndrome.

  Donor transplant option

• Polycythemia vera (PV)

  Polycythemia vera (PV) is a slow-growing blood cancer, one of the myeloproliferative neoplasms, in which the bone marrow makes too many red blood cells and may make too many white cells and platelets as well. Almost everyone with PV has a JAK2 gene change. The thicker blood raises the risk of clots, and over many years PV can change into myelofibrosis or acute myeloid leukemia.

  Not treated with transplant

• Post-essential thrombocythemia myelofibrosis (post-ET MF)

  Post-essential thrombocythemia myelofibrosis is progression of a previously established essential thrombocythemia (ET) to a fibrotic marrow disorder. Anemia, an enlarged spleen and other changes can replace the earlier pattern of mainly raised platelets.

  Donor transplant option

• Post-polycythemia vera myelofibrosis (post-PV MF)

  Post-polycythemia vera myelofibrosis is progression of previously established polycythemia vera (PV) to a fibrotic marrow disorder. Blood production and symptoms change; anemia and an enlarged spleen may develop after the earlier phase of excess red cells.

  Donor transplant option

• Primary myelofibrosis (PMF)

  Primary myelofibrosis is a blood-forming stem cell cancer that disrupts marrow function and can cause marrow scarring. Blood production may shift to the spleen and liver, leading to enlarged organs and symptoms.

  Donor transplant option

Conditions of the antibody-making cells in the marrow. Most transplants here use the person’s own cells. Explore plasma cell disorders

• AL amyloidosis (light-chain amyloidosis)

  AL amyloidosis occurs when an abnormal cell clone produces antibody light chains that misfold and damage organs. Treatment suppresses that clone; some carefully selected patients receive high-dose chemotherapy followed by their own stem cells.

  Usually the person’s own cells

• MGUS (monoclonal gammopathy of undetermined significance)

  MGUS (monoclonal gammopathy of undetermined significance) is a common condition. A small group of plasma cells makes an abnormal antibody protein, called M protein. It is not cancer and causes no symptoms. But a small share of people later develop multiple myeloma or a related disease, so it is watched with regular blood tests.

  Not treated with transplant

• Multiple myeloma

  Multiple myeloma is a cancer of antibody-producing plasma cells. Treatment combines medicines directed at the myeloma; eligible patients may receive high-dose chemotherapy followed by their own stem cells, while donor transplantation is uncommon.

  Cell or gene therapy options

• POEMS syndrome

  POEMS syndrome is a rare disorder caused by an abnormal plasma-cell population, with nerve damage and effects on several organs. Treatment targets the plasma cells; an autologous stem cell transplant is an option for eligible people with systemic disease.

  Usually the person’s own cells

• Primary plasma cell leukemia (pPCL)

  Primary plasma cell leukemia is an aggressive plasma-cell cancer with malignant plasma cells circulating in blood at diagnosis. Treatment is urgent and often combines modern myeloma medicines with selected transplant strategies.

  Usually the person’s own cells

• Smoldering multiple myeloma (SMM)

  Smoldering multiple myeloma is an early stage of myeloma that causes no symptoms or organ damage. Abnormal plasma cells and the abnormal protein they make are present at higher levels than in MGUS. Most people are watched closely; some with high-risk disease may be offered treatment to delay progression to active myeloma.

  Limited transplant role

Conditions in which the marrow cannot produce enough healthy blood cells. Causes may be inherited or acquired. Explore bone marrow failure

• Congenital amegakaryocytic thrombocytopenia (MPL-related)

  MPL-related congenital amegakaryocytic thrombocytopenia is a genetic disorder that causes too few platelets and can progress to broader marrow failure. A donor stem-cell transplant can restore blood production. Confirming the genetic cause matters because similar-looking conditions may need different treatment.

  Donor transplant option

• Diamond-Blackfan anemia (DBA)

  Diamond-Blackfan anemia, also called DBA syndrome, is a genetic condition that mainly reduces red-blood-cell production. Treatment may involve corticosteroids, transfusions with iron removal, or a donor transplant. Growth, congenital differences and cancer susceptibility also need attention.

  Donor transplant option

• Dyskeratosis congenita (DC)

  Dyskeratosis congenita is part of a group of genetic telomere biology disorders that can affect bone marrow, lungs, liver and other tissues. A donor transplant can treat severe marrow failure, but it does not correct the telomere disorder throughout the body.

  Donor transplant option

• Fanconi anemia (FA)

  Fanconi anemia is a genetic disorder of DNA repair that can affect blood production, growth and several organs, and increases cancer risk. A donor transplant can treat severe marrow failure and some blood cancers, but it does not correct the disorder throughout the body.

  Donor transplant option

• Paroxysmal nocturnal hemoglobinuria (PNH)

  Paroxysmal nocturnal hemoglobinuria, or PNH, is an acquired blood disorder in which some blood cells lack protection from complement, part of the immune system. It can cause red-cell destruction and dangerous clots. Medicines usually lead treatment; donor transplantation has a selective role.

  Limited transplant role

• Severe aplastic anemia (SAA)

  Aplastic anemia is a serious failure of blood-cell production, usually caused by an immune attack on the bone marrow. It is not a cancer. Immunosuppressive treatment and a donor stem-cell transplant are both established approaches; the best route depends on the person and their available donors.

  Donor transplant option

• Severe congenital neutropenia (SCN)

  Severe congenital neutropenia is a group of genetic disorders that cause persistently low levels of neutrophils, white blood cells that help fight infection. Growth-factor treatment benefits many people. A donor transplant is considered when infection control or marrow findings make that the safer long-term option.

  Limited transplant role

• Shwachman-Diamond syndrome (SDS)

  Shwachman-Diamond syndrome is a genetic disorder that can affect the pancreas, blood production, growth and bones. Care often combines pancreatic enzymes, nutrition support and blood monitoring. A donor transplant treats serious marrow disease, while problems outside the blood system may persist.

  Limited transplant role

Conditions carried in the genes that change how red blood cells are shaped or how long they last. Explore inherited red blood cell disorders

• Alpha thalassemia major (Hb Bart’s hydrops fetalis)

  Alpha thalassemia major is the most severe form of alpha thalassemia. Without treatment, most babies do not survive pregnancy or the first days of life. Blood transfusions given before birth now help many babies survive, and a donor stem cell transplant can cure the condition for some children.

  Donor transplant option

• Beta thalassemia major (transfusion-dependent)

  Transfusion-dependent beta-thalassemia is an inherited hemoglobin disorder that requires regular red-cell transfusions. Iron management is essential alongside transfusion. A donor transplant or an approved gene therapy may offer transfusion independence for selected people, but each requires careful assessment and long-term care.

  Cell or gene therapy options

• Congenital dyserythropoietic anemia (CDA)

  Congenital dyserythropoietic anemia (CDA) is a group of rare inherited conditions in which red blood cells do not develop normally in the bone marrow. Most people have mild to moderate anemia and are cared for with transfusions when needed and iron removal. A donor stem cell transplant is the only cure, but it is used for few people with severe disease.

  Limited transplant role

• Pyruvate kinase deficiency

  Pyruvate kinase deficiency is a genetic enzyme disorder that leaves red blood cells short of energy and causes them to break down early. Treatment is individualized and can include transfusions, iron removal and targeted medicine. Donor transplantation is a rare option for selected severe disease.

  Limited transplant role

• Sickle cell disease

  Sickle cell disease is a group of inherited hemoglobin disorders that can cause anemia, pain, infection and organ injury. Medicines, prevention and transfusion are central to care. A donor transplant or gene therapy can offer a major change in disease course for selected people, with substantial treatment risks.

  Cell or gene therapy options

Genetic conditions that affect immune defenses or regulation. Some present in infancy; others are recognized later in life. Explore inherited immune disorders

• Activated PI3K-delta syndrome (APDS)

  Activated PI3K-delta syndrome (APDS) is a rare inherited immune disorder in which an overactive enzyme keeps B and T cells from maturing properly. It can cause repeated ear, sinus and lung infections, long-lasting herpes-family virus infections, swollen lymph glands and spleen, autoimmune problems and a higher risk of lymphoma.

  Donor transplant option

• ADA-SCID (adenosine deaminase-deficient SCID)

  ADA-deficient SCID is a genetic immune disorder in which a missing enzyme allows toxic metabolites to build up, impairing infection-fighting cells. ADA deficiency can also affect organs outside the immune system and can have later-onset forms.

  Cell or gene therapy options

• Artemis-deficient SCID (DCLRE1C)

  Artemis-deficient SCID is caused by DCLRE1C variants that impair DNA repair needed to build immune-cell receptors. Severe forms lack effective T- and B-cell immunity; partial defects can present differently or later.

  Donor transplant option

• Autoimmune lymphoproliferative syndrome (ALPS)

  Autoimmune lymphoproliferative syndrome (ALPS) is a rare inherited immune disorder in which lymphocytes do not die off normally, most often because of a FAS gene change. Lymph nodes and the spleen enlarge, the immune system can attack blood cells, and the risk of lymphoma is higher.

  Limited transplant role

• CD40 ligand deficiency (X-linked hyper-IgM syndrome)

  CD40 ligand deficiency is an X-linked immune disorder that impairs communication between immune cells, including the ability to make effective antibody responses. Serious infections, neutropenia and liver or intestinal complications can occur.

  Donor transplant option

• Chediak-Higashi syndrome (CHS)

  Chediak-Higashi syndrome (CHS) is a rare inherited disorder of the immune system, blood and pigment. It causes infections, easy bleeding, light coloring of the skin, hair and eyes, and a high risk of HLH, a life-threatening inflammation. Nerve problems develop later in life. It is not a blood cancer.

  Donor transplant option

• Chronic granulomatous disease (CGD)

  Chronic granulomatous disease is a genetic disorder in which certain immune cells cannot generate a normal antimicrobial oxidative response. It causes susceptibility to particular bacterial and fungal infections and can also cause harmful inflammation.

  Donor transplant option

• Common variable immunodeficiency (CVID)

  Common variable immunodeficiency (CVID) is an immune disorder in which B cells, usually present in normal numbers, do not mature properly into antibody-making plasma cells, so antibody levels and vaccine responses are low. Repeated infections are common, and autoimmune, gut, granuloma and lymphoma complications can occur.

  Limited transplant role

• CTLA-4 haploinsufficiency (CTLA-4 insufficiency)

  CTLA-4 haploinsufficiency is a rare inherited immune disorder. A change in one copy of the CTLA4 gene leaves too little CTLA-4, a protein that acts as a brake on the immune system. It can cause low antibody levels, infections, autoimmune low blood counts, gut inflammation, swollen lymph nodes and spleen, and immune cells crowding into organs. Some people who carry the gene change never become ill.

  Donor transplant option

• DOCK8 deficiency

  DOCK8 deficiency is a genetic combined immune disorder associated with recurrent infections, severe viral skin infections, eczema and allergic disease. Some affected people also develop malignancy.

  Donor transplant option

• Familial HLH (hemophagocytic lymphohistiocytosis)

  Familial hemophagocytic lymphohistiocytosis (familial HLH) is an inherited immune disorder in which immune activation does not switch off properly. It can cause severe inflammation and organ damage; it is not a blood cancer.

  Donor transplant option

• GATA2 deficiency syndrome

  GATA2 deficiency is a genetic syndrome affecting blood-forming and immune cells. It can cause unusual infections, low blood counts and a predisposition to myelodysplastic neoplasms or acute myeloid leukemia; some people also have lymphatic or lung problems.

  Donor transplant option

• Griscelli syndrome type 2 (GS2)

  Griscelli syndrome type 2 (GS2) is a rare inherited immune disorder caused by changes in the RAB27A gene. Many people have silvery-gray hair and light skin. Most develop HLH, a life-threatening inflammation that often affects the brain. It is not a blood cancer.

  Donor transplant option

• IL7R-deficient SCID

  IL7R-deficient SCID is a genetic disorder that prevents normal T-cell development. B cells and natural-killer cells are typically present, but the lack of effective T-cell immunity leaves a child vulnerable to serious infection.

  Donor transplant option

• IPEX syndrome

  IPEX syndrome is an X-linked disorder of immune regulation caused by FOXP3 variants. The immune system can attack the intestine, skin and endocrine organs, causing severe diarrhea, eczema and autoimmune disease such as diabetes.

  Donor transplant option

• JAK3-deficient SCID

  JAK3-deficient SCID is a recessive genetic disorder that disrupts immune signaling. T cells and natural-killer cells are usually profoundly reduced, while B cells may be present but cannot provide normal protection.

  Donor transplant option

• Leukocyte adhesion deficiency type I (LAD-I)

  Leukocyte adhesion deficiency type I is an ITGB2-related immune disorder that prevents white blood cells from moving normally from the bloodstream into infected tissues. Severe disease causes recurrent infections and poor wound healing.

  Cell or gene therapy options

• LRBA deficiency

  LRBA deficiency is a rare inherited immune disorder in which the body breaks down too much CTLA-4, a protein that acts as a brake on the immune system. It causes repeated infections, low antibody levels, autoimmune disease, gut inflammation and swollen lymph nodes and spleen, usually starting in early childhood.

  Donor transplant option

• MHC class II deficiency (bare lymphocyte syndrome type II)

  MHC class II deficiency impairs the display of signals that help immune cells recognize threats and coordinate a response. It causes severe combined immune dysfunction, often with infections, chronic diarrhea and poor growth.

  Donor transplant option

• NEMO deficiency (ectodermal dysplasia with immunodeficiency)

  NEMO deficiency is a rare X-linked disorder that weakens the immune system and changes how the skin, hair, teeth and sweat glands form. Boys can get severe bacterial and mycobacterial infections, and some develop colitis or other inflammation.

  Donor transplant option

• Purine nucleoside phosphorylase (PNP) deficiency

  PNP deficiency is a genetic disorder of purine breakdown. Toxic metabolites particularly harm T-cell immunity, and affected people may have recurrent infections, autoimmunity and neurologic or developmental problems.

  Donor transplant option

• RAG1 deficiency

  RAG1 deficiency impairs the DNA rearrangement needed to build T- and B-cell receptors. Severe loss of function can cause SCID; partial function can cause Omenn syndrome or later combined immunodeficiency with infection and immune dysregulation.

  Donor transplant option

• RAG2 deficiency

  RAG2 deficiency impairs the DNA rearrangement needed to build T- and B-cell receptors. Severe loss of function can cause SCID; partial function can cause Omenn syndrome or later combined immunodeficiency with infection and immune dysregulation.

  Donor transplant option

• Reticular dysgenesis (AK2 deficiency SCID)

  Reticular dysgenesis is the most severe form of severe combined immunodeficiency (SCID). Changes in both copies of the AK2 gene leave a newborn with almost no T cells and very few or no neutrophils, the white blood cells that eat bacteria, and usually with hearing loss.

  Donor transplant option

• STAT1 gain-of-function disease

  STAT1 gain-of-function (GOF) disease is a rare inherited immune disorder in which the STAT1 signaling protein is too active. Nearly everyone has chronic mucocutaneous candidiasis (CMC), Candida infections of the mouth, skin and nails that keep returning, from early childhood. Many also have bacterial and viral infections and autoimmune problems, and some develop invasive infections, aneurysms or cancer.

  Donor transplant option

• Wiskott-Aldrich syndrome (WAS)

  Wiskott-Aldrich syndrome is an X-linked disorder affecting platelets and immune function. It can cause bleeding, eczema, infections and autoimmunity, with increased risk of some cancers.

  Cell or gene therapy options

• X-linked lymphoproliferative disease type 1 (XLP1)

  XLP1 is an SH2D1A-related immune-regulation disorder. It can cause life-threatening inflammatory illness such as HLH, abnormal antibody levels and lymphoma; Epstein–Barr virus is an important trigger, although disease is not limited to one infection.

  Donor transplant option

• X-linked severe combined immunodeficiency (X-SCID)

  IL2RG-associated SCID disrupts immune signaling needed for T-cell and natural-killer-cell development. B cells may be present but function poorly. Some IL2RG variants cause less typical, later presentations.

  Donor transplant option

• XIAP deficiency (XLP2)

  XIAP deficiency is an X-linked disorder of immune regulation, historically called XLP2. It can cause HLH, recurrent inflammation and inflammatory bowel disease, including illness that is not triggered by Epstein–Barr virus.

  Donor transplant option

• ZAP-70 deficiency

  ZAP-70 deficiency is a rare inherited immune disorder. A signaling protein that T cells need is missing or does not work. As a result, CD8 “killer” T cells are nearly absent, and the other T cells do not respond properly. Babies often have pneumonia, diarrhea, skin rashes and poor growth.

  Donor transplant option

Genetic conditions that disrupt how the body processes substances. Transplant is an option for selected disorders and stages. Explore inherited metabolic disorders

• Adult-onset metachromatic leukodystrophy (MLD)

  Adult-onset metachromatic leukodystrophy is a later form of an inherited sulfatide-storage disorder, usually caused by ARSA deficiency. It damages myelin in the nervous system and may first appear as changes in behavior, thinking or movement.

  Limited transplant role

• Alpha-mannosidosis

  Alpha-mannosidosis is a MAN2B1-related lysosomal disorder in which certain sugar-containing molecules accumulate. It can affect hearing, learning, bones, movement and immunity, with widely varying severity.

  Limited transplant role

• Cerebral adrenoleukodystrophy (cALD)

  Cerebral X-linked adrenoleukodystrophy is an ABCD1-related disorder in which inflammatory myelin damage can cause progressive neurologic loss. Not everyone with an ABCD1 variant develops cerebral disease.

  Donor transplant option

• Early-juvenile metachromatic leukodystrophy (MLD)

  Early-juvenile metachromatic leukodystrophy is a childhood form of an inherited disorder in which sulfatides accumulate and damage myelin. Movement, learning and other neurologic functions can deteriorate.

  Cell or gene therapy options

• Farber disease (acid ceramidase deficiency)

  Farber disease is an ASAH1-related lysosomal disorder in which fats called ceramides build up. It classically causes painful joints, lumps under the skin and a hoarse voice; severe forms also affect the brain, lungs, liver and spleen.

  Limited transplant role

• Fucosidosis

  Fucosidosis is a FUCA1-related lysosomal enzyme disorder. Accumulated molecules can affect development, movement, breathing, hearing, skin and the skeleton; severity varies.

  Limited transplant role

• Gaucher disease type 1

  Gaucher disease type 1 is an inherited GBA1 enzyme disorder in which a fatty substance builds up in macrophages, a kind of white blood cell. It can enlarge the spleen and liver, lower blood counts and damage bones, and it usually does not affect the brain and spinal cord.

  Limited transplant role

• Gaucher disease type 2

  Gaucher disease type 2 is the most severe form of GBA1-related Gaucher disease. It affects the brain and nerves in the first months of life and gets worse quickly, and it can also enlarge the liver and spleen and lower blood counts.

  Not treated with transplant

• Gaucher disease type 3

  Gaucher disease type 3 is a GBA1-related lysosomal disorder with both systemic and slowly progressive neurologic manifestations. It can affect blood counts, liver, spleen, bones and eye movements or other nervous-system functions.

  Limited transplant role

• Hunter syndrome (MPS II)

  Hunter syndrome (MPS II) is an inherited, X-linked condition in which the enzyme iduronate-2-sulfatase is missing, so sugar chains called GAGs build up. It almost always affects boys and can harm the airway, heart, joints and hearing and, in the severe form, the brain.

  Donor transplant option

• Hurler syndrome (severe MPS I)

  Hurler syndrome is the severe form of mucopolysaccharidosis type I, caused by IDUA deficiency. Glycosaminoglycans accumulate and can affect development, bones, joints, heart, breathing, hearing and vision.

  Donor transplant option

• I-cell disease (mucolipidosis II)

  Mucolipidosis II alpha/beta is a GNPTAB-related disorder that disrupts the delivery of several enzymes to lysosomes. It can cause severe skeletal, growth, cardiac and respiratory problems beginning very early in life.

  Limited transplant role

• Infantile Krabbe disease

  Infantile Krabbe disease is a genetic disorder, usually caused by GALC deficiency, that damages myelin in the brain and peripheral nerves. Early disease can progress quickly, making assessment before symptoms especially important.

  Donor transplant option

• Late-infantile and juvenile Krabbe disease

  Later-onset Krabbe disease is a GALC-related disorder in which myelin damage begins after the earliest infantile period. It can affect walking, vision, coordination and other neurologic functions, with variable progression.

  Donor transplant option

• Late-infantile metachromatic leukodystrophy (MLD)

  Late-infantile metachromatic leukodystrophy is a rapidly progressive early-childhood disorder, usually caused by ARSA deficiency. Accumulated sulfatides damage the insulating myelin around nerves, affecting movement and other neurologic functions.

  Cell or gene therapy options

• Late-juvenile metachromatic leukodystrophy (MLD)

  Late-juvenile metachromatic leukodystrophy is a later-childhood form of an inherited sulfatide-storage disorder. Myelin damage can affect learning, behavior, walking and other neurologic functions.

  Donor transplant option

• Maroteaux-Lamy syndrome (MPS VI)

  Maroteaux-Lamy syndrome (MPS VI) is an inherited lysosomal storage disorder caused by a shortage of the enzyme arylsulfatase B. Sugar chains called glycosaminoglycans build up and affect bones, joints, heart valves, airways, eyes and hearing. It does not usually affect thinking.

  Limited transplant role

• Niemann-Pick disease type C1 (NPC1)

  Niemann-Pick disease type C1 is the NPC1 gene form of Niemann-Pick type C, a rare inherited lysosomal disorder in which cells cannot move cholesterol and other fats. It slowly damages the brain and nerves and can affect the liver, spleen and lungs.

  Not treated with transplant

• Niemann-Pick disease type C2 (NPC2)

  NPC2-related Niemann-Pick disease type C is a genetic disorder of intracellular lipid transport. It can affect the liver, spleen, lungs and nervous system; some infants have severe pulmonary disease.

  Limited transplant role

• Niemann-Pick disease types A and B (ASMD)

  Acid sphingomyelinase deficiency (ASMD), long called Niemann-Pick disease types A, A/B and B, is a rare inherited lysosomal disorder. A missing enzyme lets a fat called sphingomyelin build up in the liver, spleen, lungs and, in some forms, the brain.

  Limited transplant role

• Severe infantile osteopetrosis (ARO)

  Severe infantile autosomal recessive osteopetrosis is a genetic disorder of bone remodeling. Overly dense bone can reduce marrow space and compress nerves. The historic word “malignant” describes severity; it does not mean cancer.

  Donor transplant option

• Sly syndrome (MPS VII)

  Sly syndrome (MPS VII) is an ultra-rare inherited lysosomal storage disorder caused by a shortage of the enzyme beta-glucuronidase. Sugar chains called glycosaminoglycans build up in many organs. Severity ranges from fluid buildup before birth (hydrops fetalis) to milder forms with survival into adulthood.

  Limited transplant role

• Wolman disease (infantile-onset LAL deficiency)

  Wolman disease is the infantile-onset form of lysosomal acid lipase deficiency, caused by changes in both copies of the LIPA gene. Fats build up in the liver, spleen, gut and adrenal glands within weeks of birth, and it is a medical emergency.

  Limited transplant role

Conditions of the immune cells that normally clear away debris and infection, when too many are made or they behave wrongly. Explore histiocytic disorders

• Blastic plasmacytoid dendritic cell neoplasm (BPDCN)

  Blastic plasmacytoid dendritic cell neoplasm (BPDCN) is a rare aggressive cancer of immature plasmacytoid dendritic cells. It often appears in the skin but can also involve marrow, blood, lymph nodes and the central nervous system.

  Donor transplant option

• Langerhans cell histiocytosis (LCH)

  Langerhans cell histiocytosis (LCH) is a clonal myeloid disorder driven by abnormal MAPK signaling. Abnormal cells accumulate in tissues such as bone, skin, pituitary, lung or other organs; the disease ranges from a single lesion to high-risk multisystem illness.

  Limited transplant role

Conditions in which the immune system attacks healthy tissue. Selected severe cases may be treated using the person’s own stem cells. Explore autoimmune conditions

• Chronic inflammatory demyelinating polyneuropathy (CIDP)

  CIDP is an immune-mediated disorder of peripheral nerves and their roots. Damage to myelin can cause progressive or relapsing weakness, altered sensation and difficulty with movement.

  Limited transplant role

• Crohn’s disease

  Crohn disease is a chronic inflammatory bowel disease that can affect different parts of the digestive tract. It can cause diarrhea, pain, weight loss, intestinal narrowing, fistulas and complications outside the bowel.

  Limited transplant role

• Early diffuse cutaneous systemic sclerosis (scleroderma)

  Early diffuse cutaneous systemic sclerosis is a form of systemic autoimmune disease involving blood vessels, skin thickening and potentially internal-organ fibrosis. It is distinct from localized scleroderma and from other systemic-sclerosis patterns.

  Usually the person’s own cells

• Evans syndrome

  Evans syndrome is a rare autoimmune condition in which the immune system destroys red blood cells and platelets, and sometimes neutrophils, a type of infection-fighting white blood cell. It often lasts for years, with flares and calmer times. In children it is often linked to an inherited immune disorder. In adults, about 1 in 5 cases comes with another illness.

  Limited transplant role

• Highly active relapsing multiple sclerosis (MS)

  Highly active relapsing multiple sclerosis is an inflammatory disease of the central nervous system with continuing relapses or new disease activity despite treatment. Damage to myelin and nerve fibers can affect movement, sensation, vision and other functions.

  Usually the person’s own cells

• Juvenile idiopathic arthritis (JIA)

  Juvenile idiopathic arthritis (JIA) is a group of long-lasting types of arthritis that begin before age 16. The immune system causes joint pain, swelling and stiffness, and in systemic JIA also fever, rash and inflammation in organs. Refractory JIA means disease that stays active despite modern medicines. The rare children considered for a transplant most often have systemic JIA.

  Limited transplant role

• Lupus (systemic lupus erythematosus)

  Systemic lupus erythematosus is an autoimmune disease that can affect skin, joints, blood, kidneys, the nervous system and other organs. Disease activity and the combination of affected organs vary widely.

  Limited transplant role

• Myasthenia gravis

  Myasthenia gravis is an autoimmune disorder that disrupts signaling from nerves to muscles. Weakness can affect the eyes, face, limbs, swallowing or breathing and often varies over time.

  Limited transplant role

• Neuromyelitis optica spectrum disorder (NMOSD)

  Neuromyelitis optica spectrum disorder is an inflammatory central-nervous-system disease that often affects the optic nerves and spinal cord. Many cases involve aquaporin-4 antibodies targeting astrocytes; it is distinct from multiple sclerosis.

  Limited transplant role

• Stiff-person syndrome and spectrum disorders

  Stiff-person spectrum disorders can cause marked muscle stiffness and painful spasms, often triggered by movement or sensory stimuli. Immune mechanisms are involved, but the spectrum includes different antibody and clinical patterns.

  Limited transplant role

Cancers that form in tissues or organs. Stem cell transplantation has a role in selected cancers; it is not routine for most. Explore solid tumors

• Atypical teratoid/rhabdoid tumor (AT/RT)

  Atypical teratoid/rhabdoid tumor (AT/RT) is a rare, aggressive tumor of the brain or spinal cord, often associated with loss of SMARCB1 function or, less commonly, SMARCA4. Tissue and molecular testing guide diagnosis and may prompt genetic counseling.

  Usually the person’s own cells

• Breast cancer

  Breast cancer is a group of cancers arising in breast tissue. Stage and tumor features, including hormone-receptor and HER2 status, strongly influence treatment; it is not ordinarily a disease treated by replacing the marrow.

  Limited transplant role

• CNS germinoma (brain germinoma)

  A CNS germinoma is a germ-cell tumor arising in the brain, often near the pineal or suprasellar regions. Its location can affect fluid circulation, vision or hormone function. It is treated differently from nongerminomatous CNS germ-cell tumors.

  Usually the person’s own cells

• CNS nongerminomatous germ cell tumor (NGGCT)

  CNS nongerminomatous germ-cell tumors are a varied group of brain tumors that includes several germ-cell histologies and mixed tumors. Imaging, tissue when appropriate and tumor markers distinguish them from pure germinoma and other brain tumors.

  Usually the person’s own cells

• Ewing sarcoma

  Ewing sarcoma is an aggressive cancer of bone or soft tissue, usually defined by a characteristic gene fusion. Treatment addresses both the visible tumor and the risk of disease elsewhere in the body.

  Usually the person’s own cells

• Medulloblastoma

  Medulloblastoma is a malignant brain tumor that begins in the cerebellum and can spread through cerebrospinal fluid. Molecular subgroup, age and disease spread help determine risk and treatment.

  Usually the person’s own cells

• Neuroblastoma

  Neuroblastoma is a cancer of immature sympathetic nerve cells, often arising in or near an adrenal gland. Its behavior ranges from tumors that can regress to high-risk metastatic disease, so treatment is strongly risk-adapted.

  Usually the person’s own cells

• Ovarian germ cell tumor

  Ovarian germ-cell tumors arise from cells in the ovary that normally develop into eggs. They include several tumor types and differ from the more common epithelial ovarian cancers.

  Usually the person’s own cells

• Pineoblastoma

  Pineoblastoma is a rare aggressive tumor of the pineal region of the brain. It can obstruct cerebrospinal fluid and spread within the central nervous system. Molecular subtype and age influence treatment and prognosis.

  Limited transplant role

• Primary mediastinal nonseminomatous germ cell tumor

  Primary mediastinal nonseminomatous germ-cell tumor is a germ-cell cancer that begins in the chest between the lungs. It is distinct from a lymphoma and from a testicular tumor that has spread to the chest.

  Usually the person’s own cells

• Retinoblastoma

  Retinoblastoma is a cancer of the retina in young children. RB1-related genetic findings can affect one or both eyes and may have implications for family testing and future cancer risk.

  Limited transplant role

• Testicular nonseminoma (NSGCT)

  Testicular nonseminomatous germ-cell tumors include several histologies, such as embryonal carcinoma, yolk-sac tumor, choriocarcinoma and teratoma, often in mixed tumors. Stage, tumor markers and the specific components guide treatment.

  Usually the person’s own cells

• Testicular seminoma

  Testicular seminoma is a germ-cell cancer that usually responds well to treatment. Pure seminoma is managed differently from nonseminomatous or mixed germ-cell tumors, so pathology and tumor markers matter.

  Usually the person’s own cells

• Wilms tumor

  Wilms tumor is a childhood kidney cancer. Stage, tissue findings, molecular features and whether one or both kidneys are affected help determine treatment; some children have an underlying genetic predisposition.

  Limited transplant role