MedGen

Adenosine deaminase (ADA) deficiency is a systemic purine metabolic disorder that primarily affects lymphocyte development, viability, and function. The ADA deficiency phenotypic spectrum includes typical early-onset severe combined immunodeficiency (ADA-SCID), diagnosed in infancy (about 80% of individuals), and less severe "delayed" or "late-onset" combined immunodeficiency (ADA-CID), diagnosed in older children and adults (15%-20% of individuals). Some healthy individuals who are deficient in red blood cell ADA (termed "partial ADA deficiency") have been discovered by screening populations or relatives of individuals with ADA-SCID. Newborn screening (NBS) for SCID uses extracts from Guthrie card dried blood spots to measure T-cell receptor excision circle (TREC) DNA by polymerase chain reaction (PCR). Screening specific for ADA deficiency can also be performed by detection of elevated levels of adenosine (Ado) and deoxyadenosine (dAdo) by tandem mass spectrometry (TMS). Both techniques can identify ADA-SCID before affected infants become symptomatic. Untreated ADA-SCID presents as life-threatening opportunistic illnesses in the first weeks to months of life with poor linear growth and weight gain secondary to persistent diarrhea, extensive dermatitis, and recurrent pneumonia. Skeletal abnormalities affecting ribs and vertebra, pulmonary alveolar proteinosis, hemolytic anemia, neurologic abnormalities, and transaminitis may also suggest untreated ADA-SCID. Characteristic immune abnormalities are lymphocytopenia (low numbers of T, B, and NK cells) combined with the absence of both humoral and cellular immune function. If immune function is not restored with enzyme replacement therapy (ERT), gene therapy, or hematopoietic stem cell transplantation (HSCT), children with ADA-SCID rarely survive beyond age one to two years. NBS for SCID does not identify individuals with the ADA-CID phenotype whose TREC numbers are above the threshold values of most screening laboratories. However, ADA-CID is identified by TMS NBS since the ADA substrates Ado and dAdo are increased. As TMS NBS for Ado/dAdo is not yet widely performed, individuals with ADA-CID are more often clinically diagnosed between ages one and ten years ("delayed" onset), or less often in the second to fourth decades ("late"/"adult" onset). Because the immunologic abnormalities are less pronounced than those of ADA-SCID, infections in ADA-CID may not be life-threatening and include recurrent otitis media, sinusitis, upper respiratory infections, and human papilloma viral infections. Untreated individuals with ADA-CID can develop over time chronic pulmonary disease, autoimmunity, atopic disease with elevated immunoglobulin E, and malignancy. [from GeneReviews]

XMEN is an X-linked recessive immunodeficiency characterized by CD4 (186940) lymphopenia, severe chronic viral infections, and defective T-lymphocyte activation (Li et al., 2011). Affected individuals have chronic Epstein-Barr virus (EBV) infection and are susceptible to the development of EBV-associated B-cell lymphoproliferative disorders. Magnesium supplementation may be therapeutic (summary by Li 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]

Lymphoproliferative syndrome-1 is an autosomal recessive primary immunodeficiency characterized by onset in early childhood of Epstein-Barr virus (EBV)-associated immune dysregulation, manifest as lymphoma, lymphomatoid granulomatosis, hemophagocytic lymphohistiocytosis, Hodgkin disease, and/or hypogammaglobulinemia. Autoimmune disorders, such as autoimmune hemolytic anemia or renal disease, may also occur. Patients show a high EBV viral load and decreased invariant natural killer T cells. It is unknown whether patients with ITK mutations are intrinsically susceptible to development of lymphoma or dysgammaglobulinemia in the absence of EBV infection (summary by Stepensky et al., 2011; Linka et al., 2012). For a discussion of genetic heterogeneity of lymphoproliferative syndrome, see XLP1 (308240). [from OMIM]

Immunodeficiency-64 with lymphoproliferation (IMD64) is an autosomal recessive primary immunodeficiency characterized by onset of recurrent bacterial, viral, and fungal infections in early childhood. Laboratory studies show variably decreased numbers of T cells, with lesser deficiencies of B and NK cells. There is impaired T-cell proliferation and activation; functional defects in B cells and NK cells may also be observed. Patients have increased susceptibility to EBV infection and may develop lymphoproliferation or EBV-associated lymphoma. Some patients may develop features of autoimmunity (summary by Salzer et al., 2016, Mao et al., 2018, and Winter et al., 2018). [from OMIM]

Immunodeficiency-76 (IMD76) is an autosomal recessive primary immunologic disorder characterized by onset of recurrent bacterial, viral, and fungal infections in early childhood. Laboratory studies show T-cell lymphopenia and may show variable B-cell or immunoglobulin abnormalities. More variable features found in some patients include lymphoma and neurologic features. Although bone marrow transplantation may be curative, many patients die in childhood (summary by Lyszkiewicz et al., 2020). [from OMIM]

Immunodeficiency-105 (IMD105) is an autosomal recessive disorder characterized by onset of recurrent infections in early infancy. Manifestations may include pneumonia, dermatitis, and lymphadenopathy. B-cell lymphoma was reported in 1 patient. Laboratory studies show decreased or absent numbers of nonfunctional T cells, normal or increased levels of B cells, hypogammaglobulinemia, and normal or low NK cells. The disorder is caused by a deficiency of transmembrane protein CD45 (PTPRC) on leukocytes, which plays an important role in T- and B-cell development (Cale et al., 1997; Kung et al., 2000). For a general phenotypic description and a discussion of genetic heterogeneity of autosomal recessive SCID, see 601457. [from OMIM]

Hyper-IgE syndrome-6 with recurrent infections (HIES6) is an autosomal dominant immunologic disorder characterized by early-childhood onset of severe refractory atopic dermatitis, IgE-mediated food and drug allergies, asthma, and eosinophilic esophagitis. Laboratory studies show increased serum IgE levels and eosinophilia. Affected individuals are susceptible to life-threatening anaphylaxis. Additional features may include allergic rhinitis, recurrent secondary infections (bacterial, viral, fungal), and short stature. Rare patients show intracerebral vascular abnormalities, including the Circle of Willis, increased risk of ruptured aneurysm, and B-cell lymphoma. The disorder results from immune dysregulation with inappropriate activation of inflammatory signaling pathways associated with a Th2 phenotype. Treatment with an IL4 (147780)/IL13 (147683) inhibitor (dupilumab) or JAK inhibitor results in clinical improvement. Sharma et al. (2023) classified this disease as a 'primary atopic disorder' (PAD). For a discussion of genetic heterogeneity of hyper-IgE syndrome, see HIES1 (147060). [from OMIM]

Immunodeficiency-84 (IMD84) is an autosomal dominant primary immunologic disorder characterized by recurrent sinopulmonary infections from childhood associated with low levels of B cells and impaired early B-cell development. There may also be variable T-cell abnormalities. Patients with IMD84 have increased susceptibility to infection with Epstein-Barr virus (EBV) and may develop lymphoma in adulthood (summary by Yamashita et al., 2021). [from OMIM]

Immunodeficiency-82 with systemic inflammation (IMD82) is a complex autosomal dominant immunologic disorder characterized by recurrent infections with various organisms, as well as noninfectious inflammation manifest as lymphocytic organ infiltration with gastritis, colitis, and lung, liver, CNS, or skin disease. One of the more common features is inflammation of the stomach and bowel. Most patients develop symptoms in infancy or early childhood; the severity is variable. There may be accompanying fever, elevated white blood cell count, decreased B cells, hypogammaglobulinemia, increased C-reactive protein (CRP; 123260), and a generalized hyperinflammatory state. Immunologic workup shows variable B- and T-cell abnormalities such as skewed subgroups. Patients have a propensity for the development of lymphoma, usually in adulthood. At the molecular level, the disorder results from a gain-of-function mutation that leads to constitutive and enhanced activation of the intracellular inflammatory signaling pathway. Treatment with SYK inhibitors rescued human cell abnormalities and resulted in clinical improvement in mice (Wang et al., 2021). [from OMIM]

Joint contractures, osteochondromas, and B-cell lymphoma (JCOSL) is an autosomal recessive systemic disorder characterized by the development of painless fixed contractures of the joints in early childhood. There is evidence of abnormal chondrocyte homeostasis, resulting in contractures, osteopenia, and the development of osteochondromas. Laboratory studies show abnormal levels and function of B- and T-cell subsets, and patients can develop B-cell lymphomas or malignancies. Despite the abnormalities in immunologic cells, immunodeficiency is not a feature of the disease, suggesting that it can be classified as a 'primary immune regulatory disorder' (Sharma et al., 2022). [from OMIM]

A type of lymphoma that originates in B-cells. [from HPO]