Congenital microvillous atrophy- MedGen UID:
- 137954
- •Concept ID:
- C0341306
- •
- Disease or Syndrome
Diarrhea-2 with microvillus atrophy, with or without cholestasis (DIAR2) is characterized by onset of intractable life-threatening watery diarrhea during infancy. Two forms are recognized: early-onset microvillus inclusion disease (MVID) with diarrhea beginning in the neonatal period, and late-onset, with first symptoms appearing after 3 or 4 months of life. Definite diagnosis is made by transmission electron microscopy demonstrating shortening or absence of apical microvilli with pathognomonic microvillus inclusions in mature enterocytes and peripheral accumulation of periodic acid-Schiff (PAS)-positive granules or vesicles in immature enterocytes (Muller et al., 2008). The natural course of MVID is often fatal, but partial or total weaning from parenteral nutrition has been described.
For a discussion of genetic heterogeneity of diarrhea, see DIAR1 (214700).
Immunodeficiency 25- MedGen UID:
- 346666
- •Concept ID:
- C1857798
- •
- Disease or Syndrome
Any severe combined immunodeficiency in which the cause of the disease is a mutation in the CD247 gene.
Bare lymphocyte syndrome type 2, complementation group A- MedGen UID:
- 395288
- •Concept ID:
- C1859534
- •
- Disease or Syndrome
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.\n\nBLS 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.\n\nIn 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).
Severe combined immunodeficiency due to LCK deficiency- MedGen UID:
- 862670
- •Concept ID:
- C4014233
- •
- Disease or Syndrome
Immunodeficiency-22 (IMD22) is an autosomal recessive disorder characterized by the onset of recurrent bacterial, viral, and fungal respiratory, gastrointestinal, and skin infections in infancy or early childhood. Immunologic workup shows severe T-cell lymphopenia, particularly affecting the CD4+ subset, and impaired proximal TCR intracellular signaling and activation. Although NK cells and B cells are normal, some patients may have hypogammaglobulinemia secondary to the T-cell defect. There are variable manifestations, likely due to the severity of the particular LCK mutation: patients may develop prominent skin lesions resembling epidermodysplasia verruciformis, gastrointestinal inflammation, and virus-induced malignancy. The disease can be fatal in childhood, but hematopoietic stem cell transplant (HSCT) may be curative (Hauck et al., 2012; Li et al., 2016; Keller et al., 2023).