This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Autoimmune Diseases, Subject name: Pathology
Decreased T cell immunity is a feature of - 
Select and explain. 
A. Digeorge syndrome, B. Hyper lgM syndrome, C. Severe congenital neutropenia, D. Chronic granulomatous diseas
A: Digeorge syndrome
Answer: A: Digeorge syndrome 
Explanation: Ans. is 'a' i.e., Di George syndrome Classification of Primary Immune Deficiency DiseasesDeficiencies of the Innate Immune Systemo Phagocytic cells# Impaired production severe congenital neutropenia (SCN)# Asplenia# Impaired adhesion leukocyte adhesion deficiency (LAD)# Impaired killing; chronic granulomatous disease (CGD)o Innate immunity receptors and signal transduction# Defects in Toll-like receptor signaling# Mendelian susceptibility to mycobacterial diseaseo Complement deficiencies# Classical, alternative, and lectin pathways# Lytic phase Deficiencies of the Adaptive Immune Systemo T lymphocyteso impaired developmento Impaired survival, migration, functionSevere combined immunedeficieneies (SOD) DiGeorge syndrome.Severe combined immunodeficiencies.Hyper-lgE syndrome (autosomal dominant).CD401 igand deficiency.Wiskott-Aldrich syndrome.Ataxia-telangiectasia and other DNA repair deficiencies.o B lymphocytesy Impaired developmenty Impaired function XL and AR agammaglobulinemiaHyper-IgM syndromeCommon variable immunodeficiencies (CVID)IgA deficiencyRegulatory Defectso Innate immunityAutoinflammatory syndrome (outside the scope of this chapter) Severe colitiso Adaptive immunityHemophagoevtic lymphohistiocytosis (HLH)Autoimmune lymphoproliferation syndrome (ALPS)Autoimmunity and inflammatory diseases (IPEX, APECED)Abbreviations: A PEC ED. autoimmune polyendocrinopathv candidiasis ectodermal dysplasia; AR, autosomal recessive,1PEX, immunodysregulation polyendocrinopathy enteropathy X-linked syndrome, XL, X-linked.