MedGen

The phenotypic spectrum of X-linked severe combined immunodeficiency (X-SCID) ranges from typical X-SCID (early-onset disease in males that is fatal if not treated with hematopoietic stem cell transplantation [HSCT] or gene therapy) to atypical X-SCID (later-onset disease comprising phenotypes caused by variable immunodeficiency, immune dysregulation, and/or autoimmunity). Typical X-SCID. Prior to universal newborn screening (NBS) for SCID most males with typical X-SCID came to medical attention between ages three and six months because of recurrent infections, persistent infections, and infections with opportunistic organisms. With universal NBS for SCID, the common presentation for typical X-SCID is now an asymptomatic, healthy-appearing male infant. Atypical X-SCID, which usually is not detected by NBS, can manifest in the first years of life or later with one of the following: recurrent upper and lower respiratory tract infections with bronchiectasis; Omenn syndrome, a clinical phenotype caused by immune dysregulation; X-SCID combined immunodeficiency (often with recurrent infections, warts, and dermatitis); immune dysregulation and autoimmunity; or Epstein-Barr virus-related lymphoproliferative complications. [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]

Any autosomal agammaglobulinemia in which the cause of the disease is a mutation in the PIK3R1 gene. [from MONDO]

Gastrointestinal defects and immunodeficiency syndrome-1 (GIDID1) is characterized by multiple intestinal atresia, in which atresia occurs at various levels throughout the small and large intestines. Surgical outcomes are poor, and the condition is usually fatal within the first month of life. Some patients exhibit inflammatory bowel disease (IBD), with or without intestinal atresia, and in some cases, the intestinal features are associated with either mild or severe combined immunodeficiency (Samuels et al., 2013; Avitzur et al., 2014; Lemoine et al., 2014). Genetic Heterogeneity of GIDID See also GIDID2 (619708), caused by mutation in the PI4KA gene (600286) on chromosome 22q11. [from OMIM]

Immunodeficiency-11A is an autosomal recessive primary immunodeficiency characterized by normal numbers of T and B lymphocytes, but defective intracellular signaling. There is a block in B-cell differentiation with increased numbers of transitional B cells and hypogammaglobulinemia, as well as decreased numbers of regulatory T cells and defects in T-cell function (summary by Greil et al., 2013 and Stepensky et al., 2013). [from OMIM]

Immunodeficiency-centromeric instability-facial anomalies syndrome-3 is an autosomal recessive disorder characterized by recurrent infections in childhood and variable dysmorphic facial features. Laboratory studies show hypomethylation of certain chromosomal regions. Additional features, including delayed development, are variable (summary by Thijssen et al., 2015). 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]

Any autosomal agammaglobulinemia in which the cause of the disease is a mutation in the CD79A gene. [from MONDO]

Immunodeficiency-centromeric instability-facial anomalies syndrome-4 is an autosomal recessive disorder characterized by recurrent infections in childhood and variable dysmorphic facial features. Laboratory studies show hypomethylation of certain chromosomal regions. Additional features, including delayed development, are variable (summary by Thijssen et al., 2015). 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 BLNK gene. [from MONDO]

Any autosomal agammaglobulinemia in which the cause of the disease is a mutation in the IGLL1 gene. [from MONDO]

Agammaglobulinemia is a primary immunodeficiency characterized by profoundly low or absent serum antibodies and low or absent circulating B cells due to an early block of B-cell development. Affected individuals develop severe infections in the first years of life. The most common form of agammaglobulinemia is X-linked agammaglobulinemia (AGMX1, XLA; 300755), also known as Bruton disease, which is caused by mutation in the BTK gene (300300). AGMX1 accounts for anywhere from 85 to 95% of males who have the characteristic findings (Lopez Granados et al., 2002; Ferrari et al., 2007). Autosomal recessive inheritance of agammaglobulinemia, which has a similar phenotype to that of the X-linked form, has been observed in a small number of families, and accounts for up to 15% of patients with agammaglobulinemia (Ferrari et al., 2007). Conley (1999) gave a comprehensive review of autosomal recessive agammaglobulinemia. Genetic Heterogeneity of Autosomal Agammaglobulinemia Autosomal agammaglobulinemia is a genetically heterogeneous disorder: see also AGM2 (613500), caused by mutation in the IGLL1 gene (146770); AGM3 (613501), caused by mutation in the CD79A gene (112205); AGM4 (613502), caused by mutation in the BLNK gene (604515); AGM5 (613506), caused by disruption of the LRRC8 gene (608360); AGM6 (612692), caused by mutation in the CD79B gene (147245); AGM7 (615214), caused by mutation in the PIK3R1 gene (171833); AGM8 (616941), caused by mutation in the TCF3 gene (147141); AGM9 (619693), caused by mutation in the SLC39A7 gene (601416); and AGM10 (619707), caused by mutation in the SPI1 gene (165170). [from OMIM]

Any autosomal agammaglobulinemia in which the cause of the disease is a mutation in the LRRC8A gene. [from MONDO]

Any autosomal agammaglobulinemia in which the cause of the disease is a mutation in the TCF3 gene. [from MONDO]

Immunodeficiency-15B (IMD15B) is an autosomal recessive primary immunodeficiency disorder characterized by onset in infancy of life-threatening bacterial, fungal, and viral infections and failure to thrive. Laboratory studies show hypo- or agammaglobulinemia with relatively normal numbers of B and T cells. However, functional studies show impaired differentiation and activation of immune cells (summary by Pannicke et al., 2013). [from OMIM]

An extremely rare type of severe combined immunodeficiency syndrome (SCID) characterized by the classical signs of T-B- SCID (severe and recurrent infections, diarrhea, failure to thrive, absence of T and B lymphocytes) associated with skeletal anomalies like short stature, bowing of the long bones and metaphyseal abnormalities of variable degree of severity. [from SNOMEDCT_US]

Bare lymphocyte syndrome type II (BLS II) is an inherited disorder of the immune system categorized as a form of combined immunodeficiency (CID). People with BLS II lack virtually all immune protection from bacteria, viruses, and fungi. They are prone to repeated and persistent infections that can be very serious or life-threatening. These infections are often caused by "opportunistic" organisms that ordinarily do not cause illness in people with a normal immune system.

BLS II is typically diagnosed in the first year of life. Most affected infants have persistent infections in the respiratory, gastrointestinal, and urinary tracts. Because of the infections, affected infants have difficulty absorbing nutrients (malabsorption), and they grow more slowly than their peers. Eventually, the persistent infections lead to organ failure. Without treatment, individuals with BLS II usually do not survive past early childhood.

In people with BLS II, infection-fighting white blood cells (lymphocytes) are missing specialized proteins on their surface called major histocompatibility complex (MHC) class II proteins, which is where the condition got its name. Because BLS II is the most common and best studied form of a group of related conditions, it is often referred to as simply bare lymphocyte syndrome (BLS). [from MedlinePlus Genetics]

Autosomal recessive agammaglobulinemia-8B (AGM8B) is characterized by onset of recurrent infections in early childhood. Laboratory studies of affected individuals show decreased circulating immunoglobulins and decreased peripheral B cells. More variable features may include dysmorphic facies and subtle abnormalities of other immune cells, such as T cells. One patient who developed childhood B-cell acute lymphocytic leukemia (B-ALL) has been described (summary by Ben-Ali et al., 2017). [from OMIM]

Immunodeficiency-93 and hypertrophic cardiomyopathy (IMD93) is an autosomal recessive disorder characterized by onset of recurrent viral and bacterial infections, particularly with encapsulated bacteria, and hypertrophic cardiomyopathy in the first months or years of life. Immunologic workup typically shows decreased circulating B cells and hypo- or agammaglobulinemia, sometimes with neutropenia or T-cell lymphocytosis, although laboratory findings may be variable among patients. Ig replacement therapy is beneficial. Cardiac involvement can also include atrial septal defect, valvular insufficiency, and pre-excitation syndrome. Rare myopathic or neurologic involvement has been reported, but these features are not consistently part of the disorder and may be related to other genetic defects (summary by Niehues et al., 2020 and Saettini et al., 2021). [from OMIM]

Autosomal dominant agammaglobulinemia-10 (AGM10) is characterized by early-childhood onset of recurrent viral and bacterial infections affecting various organ systems, particularly the sinopulmonary system. Laboratory studies show low or absent circulating B cells and hypo- or agammaglobulinemia. Affected individuals may have adverse reactions to certain vaccinations, such as the polio vaccine. Treatment with replacement Ig is effective; hematopoietic stem cell transplantation has also been reported (summary by Le Coz et al., 2021). For a discussion of genetic heterogeneity of autosomal agammaglobulinemia, see AGM1 (601495). [from OMIM]