A rare hemorrhagic disorder due to a constitutional platelet anomaly characterized by moderate to severe deficiency in both platelet alpha-granules and dense bodies, resulting in impaired platelet function and decreased aggregation responses. Patients present increased bleeding tendency with symptoms like easy bruising, or menorrhagia.

A rare, genetic, immune disease characterized by chronic neutrophilia, increase in the percentage of circulating CD34+ cells in peripheral blood, increase in granulocyte precursors in bone marrow and splenomegaly. Patients are predominantly asymptomatic, but may present with systemic inflammatory response syndrome with fever, dyspnea, tachycardia, pleural and pericardial effusion, or myelodysplastic syndrome.

An acquired form of alpha-thalassemia characterized by a myelodysplastic syndrome (MDS) or more rarely a myeloproliferative disease (MPD) associated with hemoglobin H disease (HbH).

The 5q- syndrome is a myelodysplastic syndrome characterized by a defect in erythroid differentiation. Patients have severe macrocytic anemia, normal or elevated platelet counts, normal or reduced neutrophil counts, erythroid hypoplasia in the bone marrow, and hypolobated micromegakaryocytes (Ebert et al., 2008).

Dyskeratosis congenita and related telomere biology disorders (DC/TBD) are caused by impaired telomere maintenance resulting in short or very short telomeres. The phenotypic spectrum of telomere biology disorders is broad and includes individuals with classic dyskeratosis congenita (DC) as well as those with very short telomeres and an isolated physical finding. Classic DC is characterized by a triad of dysplastic nails, lacy reticular pigmentation of the upper chest and/or neck, and oral leukoplakia, although this may not be present in all individuals. People with DC/TBD are at increased risk for progressive bone marrow failure (BMF), myelodysplastic syndrome or acute myelogenous leukemia, solid tumors (usually squamous cell carcinoma of the head/neck or anogenital cancer), and pulmonary fibrosis. Other findings can include eye abnormalities (epiphora, blepharitis, sparse eyelashes, ectropion, entropion, trichiasis), taurodontism, liver disease, gastrointestinal telangiectasias, and avascular necrosis of the hips or shoulders. Although most persons with DC/TBD have normal psychomotor development and normal neurologic function, significant developmental delay is present in both forms; additional findings include cerebellar hypoplasia (Hoyeraal Hreidarsson syndrome) and bilateral exudative retinopathy and intracranial calcifications (Revesz syndrome and Coats plus syndrome). Onset and progression of manifestations of DC/TBD vary: at the mild end of the spectrum are those who have only minimal physical findings with normal bone marrow function, and at the severe end are those who have the diagnostic triad and early-onset BMF.

RUNX1 familial platelet disorder with associated myeloid malignancies (RUNX1-FPDMM) is characterized by prolonged bleeding and/or easy bruising and an increased risk of developing a hematologic malignancy. RUNX1-FPDMM is characterized by thrombocytopenia with normal platelet size; bleeding is often greater than expected due to qualitative platelet dysfunction. Myeloid malignancies are the most common, including acute myelogenous leukemia (and myelodysplastic syndrome. T- and B-cell acute lymphoblastic leukemias and lymphomas have also been reported, as well as skin manifestations (e.g., eczema, psoriasis).

Hyper-IgM syndrome is a condition characterized by normal or increased serum IgM concentrations associated with low or absent serum IgG, IgA, and IgE concentrations, indicating a defect in the class-switch recombination (CSR) process (summary by Imai et al., 2003). For a discussion of genetic heterogeneity of immunodeficiency with hyper-IgM, see HIGM1 (308230).

LIG4 syndrome is an autosomal recessive severe combined immunodeficiency with features of radiosensitivity, chromosomal instability, pancytopenia, and developmental and growth delay. Leukemia and dysmorphic facial features have been reported in some patients (summary by van der Burg et al., 2006).

Monosomy 7 myelodysplasia and leukemia syndrome-1 (M7MLS1) is an autosomal dominant hematologic disorder with highly variable manifestations. Most patients present in early childhood with pancytopenia and dyspoietic or dysplastic changes in the bone marrow. These abnormalities are almost always associated with monosomy 7 in the bone marrow. In severely affected individuals, the phenotype progresses to frank myelodysplastic syndrome (MDS) or acute myelogenous leukemia (AML). Less severely affected individuals may have transient thrombocytopenia or anemia, or have normal peripheral blood counts with transient bone marrow abnormalities or transient monosomy 7. Germline mutations in the SAMD9L gene, located on chromosome 7q, have a gain-of-function suppressive effect on the cell cycle, resulting in decreased cellular proliferation. It is hypothesized that this germline defect leads to selective pressure favoring somatic loss of the chromosome 7 harboring the mutant allele (adaptation by aneuploidy) (summary by Wong et al., 2018). Monosomy 7 or partial deletion of the long arm of chromosome 7 (7q-) is a frequent cytogenetic finding in the bone marrow of patients with myelodysplasia and acute myelogenous leukemia. Furthermore, monosomy 7 or 7q- is the most frequent abnormality of karyotype in cases of AML that occur after cytotoxic cancer therapy or occupational exposure to mutagens. The age distribution of de novo cases shows peaks in the first and fifth decades. Monosomy 7 is found in about 5% of de novo and 40% of secondary cases of AML. These findings suggest that loss of certain genes at this region is an important event in the development of myelodysplasia (summary by Shannon et al., 1989). Genetic Heterogeneity of Monosomy 7 Myelodysplastic and Leukemia Syndrome See also M7MLS2 (619041), caused by germline mutation in the SAMD9 gene (610457) on chromosome 7q21.

Diamond-Blackfan anemia (DBA) is characterized by a profound normochromic and usually macrocytic anemia with normal leukocytes and platelets, congenital malformations in up to 50%, and growth deficiency in 30% of affected individuals. The hematologic complications occur in 90% of affected individuals during the first year of life. The phenotypic spectrum ranges from a mild form (e.g., mild anemia or no anemia with only subtle erythroid abnormalities, physical malformations without anemia) to a severe form of fetal anemia resulting in nonimmune hydrops fetalis. DBA is associated with an increased risk for acute myelogenous leukemia (AML), myelodysplastic syndrome (MDS), and solid tumors including osteogenic sarcoma.

Primary lymphedema with myelodysplasia, also known as Emberger syndrome, is a rare disorder characterized by childhood-onset lymphedema of the lower limbs, with lymphoscintigraphy suggestive of lymphatic vessel hypoplasia, and genital lymphatic abnormalities. Myelodysplasia is usually with monosomy 7. Multiple warts, deafness, and minor anomalies (mild hypotelorism, neck webbing, and slender fingers) may also be present (summary by Mansour et al., 2010).

This primary immunodeficiency, designated IMD21, DCML, or MONOMAC, is characterized by profoundly decreased or absent monocytes, B lymphocytes, natural killer (NK) lymphocytes, and circulating and tissue dendritic cells (DCs), with little or no effect on T-cell numbers. Clinical features of IMD21 are variable and include susceptibility to disseminated nontuberculous mycobacterial infections, papillomavirus infections, opportunistic fungal infections, and pulmonary alveolar proteinosis. Bone marrow hypocellularity and dysplasia of myeloid, erythroid, and megakaryocytic lineages are present in most patients, as are karyotypic abnormalities, including monosomy 7 and trisomy 8. In the absence of cytogenetic abnormalities or overt dysplasia, hypoplastic bone marrow may initially be diagnosed as aplastic anemia. Bone marrow transplantation is the only cure. Some patients may have an increased risk of miscarriage. Both autosomal dominant transmission and sporadic cases occur. Less common manifestations of GATA2 deficiency include lymphedema and sensorineural hearing loss, a phenotype usually termed 'Emberger syndrome' (614038) (summary by Bigley et al. (2011), Hsu et al. (2011), and Spinner et al. (2014)).

Myelodysplastic syndrome (MDS) is a heterogeneous group of clonal hematologic stem cell disorders characterized by ineffective hematopoiesis resulting in low blood counts, most commonly anemia, and a risk of progression to acute myeloid leukemia (AML; 601626). Blood smears and bone marrow biopsies show dysplastic changes in myeloid cells, with abnormal proliferation and differentiation of 1 or more lineages (erythroid, myeloid, megakaryocytic). MDS can be subdivided into several categories based on morphologic characteristics, such as low-grade refractory anemia (RA) or high-grade refractory anemia with excess blasts (RAEB). Bone marrow biopsies of some patients show ringed sideroblasts (RARS), which reflects abnormal iron staining in mitochondria surrounding the nucleus of erythrocyte progenitors (summary by Delhommeau et al., 2009 and Papaemmanuil et al., 2011).

Fanconi anemia (FA) is characterized by physical abnormalities, bone marrow failure, and increased risk for malignancy. Physical abnormalities, present in approximately 75% of affected individuals, include one or more of the following: short stature, abnormal skin pigmentation, skeletal malformations of the upper and/or lower limbs, microcephaly, and ophthalmic and genitourinary tract anomalies. Progressive bone marrow failure with pancytopenia typically presents in the first decade, often initially with thrombocytopenia or leukopenia. The incidence of acute myeloid leukemia is 13% by age 50 years. Solid tumors – particularly of the head and neck, skin, and genitourinary tract – are more common in individuals with FA.

Dyskeratosis congenita and related telomere biology disorders (DC/TBD) are caused by impaired telomere maintenance resulting in short or very short telomeres. The phenotypic spectrum of telomere biology disorders is broad and includes individuals with classic dyskeratosis congenita (DC) as well as those with very short telomeres and an isolated physical finding. Classic DC is characterized by a triad of dysplastic nails, lacy reticular pigmentation of the upper chest and/or neck, and oral leukoplakia, although this may not be present in all individuals. People with DC/TBD are at increased risk for progressive bone marrow failure (BMF), myelodysplastic syndrome or acute myelogenous leukemia, solid tumors (usually squamous cell carcinoma of the head/neck or anogenital cancer), and pulmonary fibrosis. Other findings can include eye abnormalities (epiphora, blepharitis, sparse eyelashes, ectropion, entropion, trichiasis), taurodontism, liver disease, gastrointestinal telangiectasias, and avascular necrosis of the hips or shoulders. Although most persons with DC/TBD have normal psychomotor development and normal neurologic function, significant developmental delay is present in both forms; additional findings include cerebellar hypoplasia (Hoyeraal Hreidarsson syndrome) and bilateral exudative retinopathy and intracranial calcifications (Revesz syndrome and Coats plus syndrome). Onset and progression of manifestations of DC/TBD vary: at the mild end of the spectrum are those who have only minimal physical findings with normal bone marrow function, and at the severe end are those who have the diagnostic triad and early-onset BMF.

Bone marrow failure syndrome-1 (BMFS1) is an autosomal dominant condition characterized by early-onset aplastic anemia or pancytopenia in some patients, and adult-onset myelodysplasia in others. Deafness or labyrinthitis also has been observed in affected individuals (Kirwan et al., 2012). Genetic Heterogeneity of Bone Marrow Failure Syndrome See also BMFS2 (615715), caused by mutation in the ERCC6L2 gene (615667) on chromosome 9q22; BMFS3 (617052), caused by mutation in the DNAJC21 gene (617048) on chromosome 5p13; BMFS4 (618116), caused by mutation in the MYSM1 gene (612176) on chromosome 1p32; BMFS5 (618165), caused by mutation in the TP53 gene (191170) on chromosome 17p13; BMFS6 (618849), caused by mutation in the MDM4 gene (602704) on chromosome 1q32; BMFS7 (AMEDS; 619151), caused by mutation in the ADH5 gene (103710) on chromosome 4q accompanied by a specific mutation in the ALDH2 gene (100650) on chromosome 12q24; and BMFS8 (ZHS; 620501), caused by mutation in the SLC30A7 gene (611149) on chromosome 1p21.

DDX41-associated familial myelodysplastic syndrome and acute myeloid leukemia (MDS/AML) is characterized by an increased risk of myeloid neoplasms, lymphoid neoplasms, adult-onset single- or multiple-lineage cytopenias (including aplastic anemia), and red blood cell macrocytosis. The most common myeloid neoplasms include MDS, AML, and therapy-related myeloid neoplasms. Chronic myelomonocytic leukemia, chronic myeloid leukemia, and myeloproliferative neoplasms are less common. Lymphoid neoplasms include non-Hodgkin lymphoma, Hodgkin lymphoma, multiple myeloma, chronic lymphocytic leukemia, and acute lymphoblastic leukemia.

MIRAGE syndrome is an acronym for the major findings of myelodysplasia, infection, restriction of growth, adrenal hypoplasia, genital phenotypes, and enteropathy. Cytopenias are typically seen soon after birth; thrombocytopenia is the most common followed by anemia and pancytopenia. Recurrent infections from early infancy include pneumonia, urinary tract infection, gastroenteritis, meningitis, otitis media, dermatitis, subcutaneous abscess, and sepsis. Reported genital phenotypes in those with 46,XY karyotype included hypospadias, microphallus, bifid shawl scrotum, ambiguous genitalia, or complete female genitalia. Hypoplastic or dysgenetic ovaries have been reported in females. Gastrointestinal complications include chronic diarrhea and esophageal dysfunction. Moderate-to-severe developmental delay is reported in most affected individuals. Autonomic dysfunction and renal dysfunction are also reported.

Specific granule deficiency-2 (SGD2) is an autosomal recessive immunologic disorder characterized by recurrent infections due to defective neutrophil development. Bone marrow findings include paucity of neutrophil granulocytes, absence of granule proteins in neutrophils, abnormal megakaryocytes, and features of progressive myelofibrosis with blasts. The disorder is apparent from infancy, and patients may die in early childhood unless they undergo hematopoietic stem cell transplantation. Most patients have additional findings, including delayed development, mild dysmorphic features, tooth abnormalities, and distal skeletal defects (Witzel et al., 2017). For a discussion of genetic heterogeneity of SGD, see SGD1 (245480).

Fanconi anemia (FA) is characterized by physical abnormalities, bone marrow failure, and increased risk for malignancy. Physical abnormalities, present in approximately 75% of affected individuals, include one or more of the following: short stature, abnormal skin pigmentation, skeletal malformations of the upper and/or lower limbs, microcephaly, and ophthalmic and genitourinary tract anomalies. Progressive bone marrow failure with pancytopenia typically presents in the first decade, often initially with thrombocytopenia or leukopenia. The incidence of acute myeloid leukemia is 13% by age 50 years. Solid tumors – particularly of the head and neck, skin, and genitourinary tract – are more common in individuals with FA.

Dyskeratosis congenita and related telomere biology disorders (DC/TBD) are caused by impaired telomere maintenance resulting in short or very short telomeres. The phenotypic spectrum of telomere biology disorders is broad and includes individuals with classic dyskeratosis congenita (DC) as well as those with very short telomeres and an isolated physical finding. Classic DC is characterized by a triad of dysplastic nails, lacy reticular pigmentation of the upper chest and/or neck, and oral leukoplakia, although this may not be present in all individuals. People with DC/TBD are at increased risk for progressive bone marrow failure (BMF), myelodysplastic syndrome or acute myelogenous leukemia, solid tumors (usually squamous cell carcinoma of the head/neck or anogenital cancer), and pulmonary fibrosis. Other findings can include eye abnormalities (epiphora, blepharitis, sparse eyelashes, ectropion, entropion, trichiasis), taurodontism, liver disease, gastrointestinal telangiectasias, and avascular necrosis of the hips or shoulders. Although most persons with DC/TBD have normal psychomotor development and normal neurologic function, significant developmental delay is present in both forms; additional findings include cerebellar hypoplasia (Hoyeraal Hreidarsson syndrome) and bilateral exudative retinopathy and intracranial calcifications (Revesz syndrome and Coats plus syndrome). Onset and progression of manifestations of DC/TBD vary: at the mild end of the spectrum are those who have only minimal physical findings with normal bone marrow function, and at the severe end are those who have the diagnostic triad and early-onset BMF.

Shwachman-Diamond syndrome (SDS) is characterized by: exocrine pancreatic dysfunction with malabsorption, malnutrition, and growth failure; hematologic abnormalities with single- or multilineage cytopenias and susceptibility to myelodysplasia syndrome (MDS) and acute myelogeneous leukemia (AML); and bone abnormalities. In almost all affected children, persistent or intermittent neutropenia is a common presenting finding, often before the diagnosis of SDS is made. Short stature and recurrent infections are common.

Severe congenital neutropenia-3 is an autosomal recessive bone marrow failure disorder characterized by low numbers of neutrophils, increased susceptibility to bacterial and fungal infections, and increased risk of developing myelodysplastic syndrome or acute myeloid leukemia. In addition, patients with HAX1 mutations affecting both isoform A and B of the gene develop neurologic abnormalities (summary by Boztug et al., 2010). The Swedish physician Rolf Kostmann (1956) described an autosomal recessive hematologic disorder, termed infantile agranulocytosis, with severe neutropenia with an absolute neutrophil count below 0.5 x 10(9)/l and early onset of severe bacterial infections. The disorder was later termed Kostmann syndrome (Skokowa et al., 2007). Lekstrom-Himes and Gallin (2000) discussed severe congenital neutropenia in a review of immunodeficiencies caused by defects in phagocytes. In addition to Kostmann agranulocytosis, recessively inherited neutropenic syndromes include congenital neutropenia with eosinophilia (257100), Chediak-Higashi syndrome (214500), and Fanconi pancytopenic syndrome (see 227650). For a phenotypic description and a discussion of genetic heterogeneity of severe congenital neutropenia, see SCN1 (202700).

VEXAS (vacuoles, E1 enzyme, X-linked, autoinflammatory, somatic syndrome) is an adult-onset inflammatory disease that primarily affects males and is caused by somatic, not germline, mutations. The disorder is characterized by adult onset of rheumatologic symptoms at a mean age of 64 years. Features include recurrent fevers, pulmonary and dermatologic inflammatory manifestations, vasculitis, deep vein thrombosis, arthralgias, and ear and nose chondritis. Laboratory studies indicate hematologic abnormalities, including macrocytic anemia, as well as increased levels of acute-phase reactants; about half of patients have positive autoantibodies. Bone marrow biopsy shows degenerative vacuolization restricted to myeloid and erythroid precursor cells, as well as variable hematopoietic dyspoiesis and dysplasias. The condition does not respond to rheumatologic medications and the features may result in premature death (summary by Beck et al., 2020).

Monosomy 7 myelodysplasia and leukemia syndrome-2 (M7MLS2) is an autosomal dominant hematologic disorder characterized by onset of pancytopenia, acute myelogenous leukemia (AML), and variable features of myelodysplastic syndrome (MDS) usually in the first decades of life. Bone marrow cells show monosomy 7. Germline mutations in the SAMD9 gene, located on chromosome 7q, have a gain-of-function suppressive effect on the cell cycle, resulting in decreased cellular proliferation. It is hypothesized that this germline defect leads to selective pressure favoring somatic loss of the chromosome 7 harboring the mutant allele (adaptation by aneuploidy) (summary by Wong et al., 2018). For a discussion of genetic heterogeneity of monosomy 7 myelodysplasia and leukemia syndrome, see 252270.

AMED syndrome (AMEDS) is an autosomal recessive digenic multisystem disorder characterized by global developmental delay with impaired intellectual development, onset of bone marrow failure and myelodysplastic syndrome (MDS) in childhood, and poor overall growth with short stature (summary by Oka et al., 2020). For a discussion of genetic heterogeneity of bone marrow failure syndrome (BMFS), see BMFS1 (614675).

Immunodeficiency-55 is an autosomal recessive primary immunodeficiency characterized by intrauterine growth retardation, natural killer (NK) cell deficiency, and chronic neutropenia. Most patients also have postnatal growth retardation. Other clinical manifestations include mild facial dysmorphism, dry or eczematous skin, and recurrent infections with both viruses and bacteria. The disorder appears to result from a defect in DNA replication causing blockade of immune cell differentiation in the bone marrow, particularly affecting NK cells (summary by Cottineau et al., 2017).

Dyskeratosis congenita and related telomere biology disorders (DC/TBD) are caused by impaired telomere maintenance resulting in short or very short telomeres. The phenotypic spectrum of telomere biology disorders is broad and includes individuals with classic dyskeratosis congenita (DC) as well as those with very short telomeres and an isolated physical finding. Classic DC is characterized by a triad of dysplastic nails, lacy reticular pigmentation of the upper chest and/or neck, and oral leukoplakia, although this may not be present in all individuals. People with DC/TBD are at increased risk for progressive bone marrow failure (BMF), myelodysplastic syndrome or acute myelogenous leukemia, solid tumors (usually squamous cell carcinoma of the head/neck or anogenital cancer), and pulmonary fibrosis. Other findings can include eye abnormalities (epiphora, blepharitis, sparse eyelashes, ectropion, entropion, trichiasis), taurodontism, liver disease, gastrointestinal telangiectasias, and avascular necrosis of the hips or shoulders. Although most persons with DC/TBD have normal psychomotor development and normal neurologic function, significant developmental delay is present in both forms; additional findings include cerebellar hypoplasia (Hoyeraal Hreidarsson syndrome) and bilateral exudative retinopathy and intracranial calcifications (Revesz syndrome and Coats plus syndrome). Onset and progression of manifestations of DC/TBD vary: at the mild end of the spectrum are those who have only minimal physical findings with normal bone marrow function, and at the severe end are those who have the diagnostic triad and early-onset BMF.

Tessadori-Bicknell-van Haaften neurodevelopmental syndrome-4 (TEBIVANED4) is characterized by global developmental delay with poor overall growth, variably impaired intellectual development, learning difficulties, distal skeletal anomalies, and dysmorphic facies. Some patients have visual or hearing deficits. The severity and manifestations of the disorder are highly variable (Tessadori et al., 2022). For a discussion of genetic heterogeneity of TEBIVANED, see TEBIVANED1 (619758).

Telomere-related pulmonary fibrosis and/or bone marrow failure syndrome-7 (PFBMFT7) is an autosomal dominant disorder characterized by variable manifestations associated with shortened telomeres. Features can include pulmonary fibrosis, emphysema, anemia, lymphopenia, liver involvement with portal hypertension and hepatopulmonary syndrome, premature graying of the hair, nail dystrophy, and predisposition to squamous cell cancers or myelodysplasia (Stanley et al., 2016). For a discussion of genetic heterogeneity of telomere-related pulmonary fibrosis and/or bone marrow failure syndromes, see PFBMFT1 (614742).