MedGen

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). [from OMIM]

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)). [from OMIM]

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). [from OMIM]

A clonal expansion of myeloid blasts in the bone marrow, blood or other tissues. The classification of acute myeloid leukemias (AMLs) encompasses four major categories: 1) AML with recurrent genetic abnormalities; 2) AML with multilineage dysplasia; 3) Therapy-related AML; 4) AML not otherwise specified. The required bone marrow or peripheral blood blast percentage for the diagnosis of AML is 20% (WHO classification) [from NCBI]