DiGeorge Syndrome

DiGeorge syndrome (Chromosome 22q11.2 deletion syndrome or Velocardiofacial syndrome) is associated with a T-lymphocyte immunodeficiency.  The features of DiGeorge syndrome vary, but can affect many parts of the body. It occurs in approximately 1:4000 births, and the incidence is increasing due to affected parents bearing their own affected children. The manifestations of this syndrome cross all… Read more »

Hereditary angioneurotic edema, C1 inhibitor deficiency

Hereditary angioneurotic edema (HAE) is due to C1 inhibitor deficiency (responsible for dissociation of activated C1 by binding to C1r2C1s2 complex). It is clinically the most important complement system deficiency. Although rare, hereditary angioneurotic edema can have terrible consequences due to slow or missed diagnoses. Laryngeal edema can result in asphyxiation; abdominal attacks can lead to unnecessary surgery and… Read more »

IgA deficiency

It is the most common immunodeficiency (1:700 in Caucasians – rare in others). Patients tend to develop immune-complex disease (type III hypersensitivity). Total immunoglobulin A deficiency (IgAD) is defined as an undetectable serum immunoglobulin A (IgA) level at a value < 5 mg/dL. Partial IgAD refers to detectable but decreased IgA levels that are more than… Read more »

Autosomal Dominant

Common Autosomal Dominant Disorders Include: DiGeorge syndrome Familial hypercholesterolemia Felty’s syndrome Gardner’s Syndrome Huntington’s Disease Hereditary spherocytosis Holt–Oram syndrome Hypertrophic cardiomyopathy Marfan syndrome Medullary cystic kidney disease Multiple endocrine neoplasia Noonan syndrome Peutz–Jeghers syndrome Short QT syndrome Tuberous sclerosis Von Hippel–Lindau disease Von Willebrand disease

X-linked agammaglobulinemia

Affected males have no B-cells and no serum immunoglobulins. They have very small lymph nodes and no tonsils. Bone marrow contains adequate number of pre-B-cells, but maturation is arrested at that point. Patients are protected by maternal immunoglobulins for first 6-12 months of life. Recurrent pyogenic infections develop after the first year of life. These… Read more »

Immunodeficiency with Increased IgM (HIGM)

Patients are IgA and IgG deficient but produce large amounts of polyclonal IgM. It is caused by the inability of immune system to make switch from IgM to IgG and other classes of immunoglobulins. Patients are susceptible to pyogenic infections and should be treated with intravenous gammaglobulins. Also, they form IgM antibodies directed against neutrophils,… Read more »

Defects in complement proteins

Deficiency of the classical pathway components (C1q, C1r, C1s, C2 and C4). Propensity to immune-complex diseases (like SLE). Deficiency of C3, factor H, and factor I. Propensity to pyogenic infections (because of C3 role in opsonization). Deficiency of terminal components (C5, C6, C7, C8) and alternative pathway (properdin and factor D). Propensity for infections with… Read more »

Common variable immunodeficiency, CVID

Common Variable Immunodeficiency Disease is the most common acquired agammaglobulinemia that occurs in the second and third decade of life. Males and females are equally affected. The cause is unknown, but viral infection (Epstain-Barr) has been implicated. B-cells are present but do not produce IgG’s.  The activation of B-cells by the T-cells is defective. Patients… Read more »


Anterior uveitis affects the front of the eye (usually the iris) and is the most common type. Only one eye is usually affected. Symptoms ~an aching, painful, red eye ~blurred or cloudy vision, ~a small pupil, ~an iris that may have a slightly different color ~sensitivity to light (photophobia), ~floaters (dots that move across the field of… Read more »

Scombroid Toxicity

Presentation: Scombroid fish poisoning is characterized by the sudden onset of diarrhea, wheezing, palpatations, headache, and flushing.  Abdominal pain, nausea, or a sense of anxiety or unease is also reported. This occurs from the ingestion of certain types of fish such as tuna, mackerel, bonita, mahi-mahi, and other fish. Look for someone having had sushi recently. …. Read more »