MedGen

Adenosine deaminase (ADA) deficiency is a systemic purine metabolic disorder that primarily affects lymphocyte development, viability, and function. The clinical phenotypic spectrum includes: Severe combined immunodeficiency disease (SCID), often diagnosed by age six months and usually by age 12 months; Less severe "delayed" onset combined immune deficiency (CID), usually diagnosed between age one and ten years; "Late/adult onset" CID, diagnosed in the second to fourth decades; Benign "partial ADA deficiency" (very low or absent ADA activity in erythrocytes but greater ADA activity in nucleated cells), which is compatible with normal immune function. Infants with typical early-onset ADA-deficient SCID have failure to thrive and opportunistic infections associated with marked depletion of T, B, and NK lymphocytes, and an absence of both humoral and cellular immune function. If immune function is not restored, children with ADA-deficient SCID rarely survive beyond age one to two years. Infections in delayed- and late-onset types (commonly, recurrent otitis, sinusitis, and upper respiratory) may initially be less severe than those in individuals with ADA-deficient SCID; however, by the time of diagnosis these individuals often have chronic pulmonary insufficiency and may have autoimmune phenomena (cytopenias, anti-thyroid antibodies), allergies, and elevated serum concentration of IgE. The longer the disorder goes unrecognized, the more immune function deteriorates and the more likely are chronic sequelae of recurrent infection. [from GeneReviews]

X-linked agammaglobulinemia (XLA) is characterized by recurrent bacterial infections in affected males in the first two years of life. Recurrent otitis is the most common infection prior to diagnosis. Conjunctivitis, sinopulmonary infections, diarrhea, and skin infections are also frequently seen. Approximately 60% of individuals with XLA are recognized as having immunodeficiency when they develop a severe, life-threatening infection such as pneumonia, empyema, meningitis, sepsis, cellulitis, or septic arthritis. S pneumoniae and H influenzae are the most common organisms found prior to diagnosis and may continue to cause sinusitis and otitis after diagnosis and the initiation of gammaglobulin substitution therapy. Severe, difficult-to-treat enteroviral infections (often manifest as dermatomyositis or chronic meningoencephalitis) can be prevented by this treatment. The prognosis for individuals with XLA has improved markedly in the last 25 years as a result of earlier diagnosis, the development of preparations of gammaglobulin that allow normal concentrations of serum IgG to be achieved, and more liberal use of antibiotics. [from GeneReviews]

Nijmegen breakage syndrome (NBS) is characterized by progressive microcephaly, early growth deficiency that improves with age, recurrent respiratory infections, an increased risk for malignancy (primarily lymphoma), and premature ovarian failure in females. Developmental milestones are attained at the usual time during the first year; however, borderline delays in development and hyperactivity may be observed in early childhood. Intellectual abilities tend to decline over time. Recurrent pneumonia and bronchitis may result in respiratory failure and early death. Other reported malignancies include solid tumors (e.g., medulloblastoma, glioma, rhabdomyosarcoma). [from GeneReviews]

Severe combined immunodeficiency refers to a genetically and clinically heterogeneous group of disorders with defective cellular and humoral immune function. Patients with SCID present in infancy with recurrent, persistent infections by opportunistic organisms, including Candida albicans, Pneumocystis carinii, and cytomegalovirus, among many others. Laboratory analysis shows profound lymphopenia with diminished or absent immunoglobulins. The common characteristic of all types of SCID is absence of T cell-mediated cellular immunity due to a defect in T-cell development. Without treatment, patients usually die within the first year of life. The overall prevalence of all types of SCID is approximately 1 in 75,000 births (Fischer et al., 1997; Buckley, 2004). Genetic Heterogeneity of SCID SCID can be divided into 2 main classes: those with B lymphocytes (B+ SCID) and those without (B- SCID). Presence or absence of NK cells is variable within these groups. The most common form of SCID is X-linked T-, B+, NK- SCID (SCIDX1; 300400) caused by mutation in the IL2RG gene (308380) on chromosome Xq13.1. Autosomal recessive SCID includes T-, B-, NK+ SCID, caused by mutation in the RAG1 and RAG2 genes on 11p13; T-, B+, NK- SCID (600802), caused by mutation in the JAK3 gene (600173) on 19p13; T-, B+, NK+ SCID (IMD104; 608971), caused by mutation in the IL7R gene (146661) on 5p13; T-, B+, NK+ SCID (IMD105; 619924), caused by mutation in the CD45 gene (PTPRC; 151460) on 1q31-q32; T-, B+, NK+ SCID (IMD19; 615617), caused by mutation in the CD3D gene (186790) on 11q23; T-, B-, NK- SCID (102700) caused by mutation in the ADA (608958) gene on 20q13; and T-, B-, NK+ SCID with sensitivity to ionizing radiation (602450), caused by mutation in the Artemis gene (DCLRE1C; 605988) on 10p13 (Kalman et al., 2004); and T-, B-, NK+ SCID with microcephaly, growth retardation, and sensitivity to ionizing radiation (611291), caused by mutation in the NHEJ1 gene (611290) on 2q35. Approximately 20 to 30% of all SCID patients are T-, B-, NK+, and approximately half of these patients have mutations in the RAG1 or RAG2 genes (Schwarz et al., 1996; Fischer et al., 1997). [from OMIM]

Omenn syndrome is an autosomal recessive disorder characterized by severe combined immunodeficiency (SCID) associated with erythrodermia, hepatosplenomegaly, lymphadenopathy, and alopecia. B cells are mostly absent, T-cell counts are normal to elevated, and T cells are frequently activated and express a restricted T-cell receptor (TCR) repertoire (summary by Ege et al., 2005). Another distinct form of familial histiocytic reticulocytosis (267700) is caused by mutation in the perforin-1 gene (PRF1; 170280) on chromosome 10q22. [from OMIM]

Common variable immunodeficiency (CVID) is a clinically and genetically heterogeneous group of disorders characterized by antibody deficiency, hypogammaglobulinemia, recurrent bacterial infections, and an inability to mount an antibody response to antigen. The defect results from a failure of B-cell differentiation and impaired secretion of immunoglobulins; the numbers of circulating B cells are usually in the normal range, but can be low. Most individuals with CVID have onset of infections after age 10 years. CVID represents the most common form of primary immunodeficiency disorders and is the most common form of primary antibody deficiency. Approximately 10 to 20% of patients with a diagnosis of CVID have a family history of the disorder (reviews by Chapel et al., 2008, Conley et al., 2009, and Yong et al., 2009). Genetic Heterogeneity of Common Variable Immunodeficiency Common variable immunodeficiency is a genetically heterogeneous disorder. See also CVID2 (240500), caused by mutation in the TACI gene (TNFRSF13B; 604907); CVID3 (613493), caused by mutation in the CD19 gene (107265); CVID4 (613494), caused by mutation in the BAFFR gene (TNFRSF13C; 606269); CVID5 (613495), caused by mutation in the CD20 gene (112210); CVID6 (613496), caused by mutation in the CD81 gene (186845); CVID7 (614699), caused by mutation in the CD21 gene (CR2; 120650); CVID8 (614700), caused by mutation in the LRBA gene (606453); CVID10 (615577), caused by mutation in the NFKB2 gene (164012); CVID11 (615767), caused by mutation in the IL21 gene (605384); CVID12 (616576), caused by mutation in the NFKB1 gene (164011); CVID13 (616873), caused by mutation in the IKZF1 gene (603023); CVID14 (617765), caused by mutation in the IRF2BP2 gene (615332); and CVID15 (620670), caused by heterozygous mutation in the SEC61A1 gene (609213). The disorder formerly designated CVID9 has been found to be a form of autoimmune lymphoproliferative disorder; see ALPS3 (615559). [from OMIM]

Severe combined immunodeficiency (SCID) due to DCLRE1C deficiency is a type of SCID (see this term) characterized by severe and recurrent infections, diarrhea, failure to thrive, and cell sensitivity to ionizing radiation. [from ORDO]

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]

Immunodeficiency-36 with lymphoproliferation (IMD36) is an autosomal dominant primary immunodeficiency with a highly heterogeneous clinical phenotype, characterized primarily by recurrent respiratory tract infections, lymphoproliferation, and antibody deficiency. Other features include growth retardation, mild neurodevelopmental delay, and autoimmunity. The major complication is development of B-cell lymphoma (Elkaim et al., 2016). [from OMIM]

Severe congenital neutropenia inherited in an autosomal dominant pattern and caused by mutation(s) in the GFI1 gene, encoding zinc finger protein Gfi-1. [from NCI]

Common variable immunodeficiency-8 with autoimmunity is an autosomal recessive disorder of immune dysregulation. Affected individuals have early childhood onset of recurrent infections, particularly respiratory infections, and also develop variable autoimmune disorders, including idiopathic thrombocytopenic purpura, autoimmune hemolytic anemia, and inflammatory bowel disease. The presentation and phenotype are highly variable, even within families (summary by Lopez-Herrera et al., 2012 and Alangari et al., 2012). Immunologic findings are also variable and may include decreased B cells, hypogammaglobulinemia, and deficiency of CD4+ T regulatory (Treg) cells (Charbonnier et al., 2015). For a general description and a discussion of genetic heterogeneity of common variable immunodeficiency, see CVID1 (607594). [from OMIM]

A rare, genetic, non-severe combined immunodeficiency disease characterized by immunodeficiency (manifested by recurrent and/or severe bacterial and viral infections), destructive noninfectious granulomas involving skin, mucosa and internal organs, and various autoimmune manifestations (including cytopenias, vitiligo, psoriasis, myasthenia gravis, enteropathy). Immunophenotypically, T-cell and B-cell lymphopenia, hypogammaglobulinemia, abnormal specific antibody production and impaired T-cell function are observed. [from ORDO]

Sideroblastic anemia with B-cell immunodeficiency, periodic fevers, and developmental delay (SIFD) is an autosomal recessive syndromic disorder characterized by onset of severe sideroblastic anemia in the neonatal period or infancy. Affected individuals show delayed psychomotor development with variable neurodegeneration. Recurrent periodic fevers without an infectious etiology occur throughout infancy and childhood; immunologic work-up shows B-cell lymphopenia and hypogammaglobulinemia. Other more variable features include sensorineural hearing loss, retinitis pigmentosa, nephrocalcinosis, and cardiomyopathy. Death in the first decade may occur (summary by Wiseman et al., 2013). [from OMIM]

Common variable immunodeficiency-13 (CVID13) is an autosomal dominant primary immunodeficiency disorder characterized by recurrent bacterial infections, mainly affecting the respiratory tract, and associated with hypogammaglobulinemia and decreased numbers of B cells. The age at onset of clinical features can range from infancy to adulthood, and some patients may have a mild disorder or even remain clinically asymptomatic (summary by Kuehn et al., 2016). For a general description and a discussion of genetic heterogeneity of common variable immunodeficiency, see CVID1 (607594). [from OMIM]

Immunodeficiency-41 is an autosomal recessive complex disorder of immune dysregulation. Affected individuals present in infancy with recurrent viral, fungal, and bacterial infections, lymphadenopathy, and variable autoimmune features, such as autoimmune enteropathy and eczematous skin lesions. Immunologic studies show a defect in T-cell regulation (summary by Goudy et al., 2013). [from OMIM]

Immunodeficiency, centromeric instability, and facial dysmorphism (ICF) syndrome is a rare autosomal recessive disorder characterized by facial dysmorphism, immunoglobulin deficiency resulting in recurrent infections, and mental retardation. Laboratory studies of patient cells show hypomethylation of satellite regions of chromosomes 1, 9, and 16, as well as pericentromeric chromosomal instability in response to phytohemagglutinin stimulation (summary by de Greef et al., 2011). For a discussion of genetic heterogeneity of immunodeficiency-centromeric instability-facial anomalies syndrome, see ICF1 (242860). [from OMIM]

Any autosomal agammaglobulinemia in which the cause of the disease is a mutation in the CD79B gene. [from MONDO]

Idiopathic CD4 lymphopenia (ICL) is a rare and heterogeneous syndrome defined by a reproducible reduction in the CD4 T-lymphocyte count (less than 300 cells per microliter or less than 20% of total T cells) in the absence of HIV infection or other known causes of immunodeficiency. ICL predisposes to infections and malignancy (summary by Gorska and Alam, 2012). [from OMIM]

Periodic fever, immunodeficiency, and thrombocytopenia syndrome (PFITS) is an autosomal recessive immunologic disorder with variable manifestations. Common features include early-onset recurrent respiratory infections, stomatitis, and cutaneous infections. Organisms usually include bacteria such as pneumococcus, Staphylococcus, and H. influenzae, but severe viral infections, including varicella, may also occur. Laboratory investigations may show neutropenia, neutrophilia, leukocytosis, or lymphopenia, although levels of immune cells may also be normal. Detailed studies often show impaired neutrophil chemotaxis associated with increased or abnormal F-actin levels, and impaired, normal, or even increased oxidative burst, depending on the stimulus. B- and T-cell abnormalities have also been observed. Some patients develop autoimmune manifestations, including chronic thrombocytopenia, anemia, and periodic fevers, associated with activation of the inflammasome. Early death may occur; however, hematopoietic stem cell transplantation may be curative (summary by Kuhns et al., 2016, Standing et al., 2017, and Pfajfer et al., 2018). [from OMIM]

Immunodeficiency-73B with defective neutrophil chemotaxis (IMD73B) is an autosomal dominant immunologic disorder characterized by onset of recurrent infections in infancy or early childhood. Affected individuals develop respiratory infections, cellulitis, and severe invasive infections or sepsis; organisms include bacteria such as Staphylococcus, as well as viruses, fungi, and mycobacterial species. Laboratory studies show variable abnormalities, including B- and T-cell lymphopenia, decreased immunoglobulin subsets, decreased TRECs and dysfunctional T cells, decreased NK cells, neutropenia, and impaired neutrophil chemotaxis. Hematopoietic stem cell transplantation is curative (summary by Hsu et al., 2019; review by Lougaris et al., 2020). In a review of autosomal forms of chronic granulomatous disease (see 306400 for genetic heterogeneity of CGD), Roos et al. (2021) noted that patients with RAC2 mutations may manifest CGD-like symptoms due to defects in neutrophil NADPH oxidase activity. [from OMIM]