Bare lymphocyte syndrome type I (BLS I) Overview Bare lymphocyte syndrome type I (BLS I) is a rare, inherited primary immunodeficiency caused by a lack of Major Histocompatibility Complex (MHC) class I proteins on cell surfaces, leading to recurrent, severe bacterial infections, often in the lungs and airways. It is caused by genetic mutations, notably in or genes, resulting in severe infections starting in childhood. According to the Immune Deficiency Foundation, management often requires diligent infection control and antibiotic treatment. Symptoms Recurrent Respiratory Infections: Frequent, severe bacterial infections in the lungs and airways (bronchitis, pneumonia, sinusitis) that often start in childhood. Bronchiectasis: Chronic lung damage, a common result of recurrent respiratory infections. Skin Lesions/Ulcers: Development of necrotic skin ulcers, often appearing in adolescence or young adulthood, typically on the face, arms, and legs. Chronic Infections: Increased ...
X-linked hyper IgM syndrome Overview X-linked hyper IgM syndrome (XHIGM, or HIGM1) is a rare primary immunodeficiency caused by mutations in the CD40LG gene on the X chromosome. Primarily affecting males, it causes low levels of IgG, IgA, and IgE, and normal/high IgM. This results in severe recurrent infections, often starting in infancy, with significant risk of opportunist infections, neutropenia, and liver disease, requiring lifelong treatment or Symptoms Recurrent Infections: Infants often experience infections early in life, including pneumonia, sepsis, sinusitis, and otitis media. Opportunistic Infections: Susceptibility to unusual infections, particularly Pneumocystis jirovecii pneumonia (PCP) and Cryptosporidium diarrhea. Gastrointestinal Distress: Chronic diarrhea and liver disease, including sclerosing cholangitis, which may be caused by Cryptosporidium. Neutropenia: Intermittent or persistent low white blood cell count, often leading to mouth ulcers and skin infection...