<unk>  syndromes <unk>  are a heterogeneous group of diseases owing to numerous molecular defects in the development and function of both T and B cells.<unk>  is a life-threatening condition of overwhelming infections, typically in the first year of life, unless the underlying defect is corrected. The accepted classification system for<unk>  is based upon particular molecular defect, which is detected. The most common genetic condition responsible for<unk>  is a mutation of the common γ chain of the interleukin (IL) receptors, and accounts for approximately 50% of all patients with<unk> . Adenosine deaminase (ADA) deficiency is an another significant mutation accounts for 20% of all<unk>  cases. Symptoms of<unk>  are recurrent<unk>  infections, chronic diarrhea, and failure to thrive (FTT). Without newborn screening for<unk> , a diagnosis is often not made until the infant develops<unk> l episodes of<unk>  infections. Early diagnosis through population-wide newborn screening and early hematopoietic cell transplantation (HCT) improve outcomes. Among patients transplanted under 3.5 months of age without infection, survival post-transplant is about 95 percent, and overall survival is 90 percent.
Severe combined immunodeficiency
Combined immunodeficiency
Common variable immunodeficiency
X-linked severe combined immunodeficiency
X-linked agammaglobulinemia
Primary immunodeficiency
Wiskott-Aldrich syndrome
Chédiak-Higashi syndrome