There are three major categories of antibody deficiencies: (a) defects in early B cell development, (b) hyper-IgM syndromes (also called class switch recombination defects), and (c) common variable immunodeficiency (CVID). Category (b), hyper-IgM syndrome (HIM), represents a group of distinct entities characterized by defective normal or elevated IgM in the presence of diminished IgG and IgA levels. Seventy per cent of the cases are X-linked in inheritance, and others are autosomal recessive. In the autosomal recessive hyper IgM syndromes, the problem lies in the nucleotide-editing enzymes AICD or UNG. These enzymes are only present in the germinal center B cells, and defects in either disrupt B-cell development and antibody production. Patients with these syndromes typically have recurrent bacterial infections and often have lymphoid hyperplasia.
Category
Immune system disease
Brite
Human diseases in ICD-11 classification [BR:br08403]
04 Diseases of the immune system
Primary immunodeficiencies
4A01 Primary immunodeficiencies due to disorders of adaptive immunity
H00086 Immunodeficiency with hyper-IgM
Pathway-based classification of diseases [BR:br08402]
Replication, repair and transcription
nt06504 Base excision repair
H00086 Immunodeficiency with hyper-IgM
Signal transduction
nt06516 TNF signaling
H00086 Immunodeficiency with hyper-IgM
Revy P, Muto T, Levy Y, Geissmann F, Plebani A, Sanal O, Catalan N, Forveille M, Dufourcq-Labelouse R, Gennery A, Tezcan I, Ersoy F, Kayserili H, Ugazio AG, Brousse N, Muramatsu M, Notarangelo LD, Kinoshita K, Honjo T, Fischer A, Durandy A
Title
Activation-induced cytidine deaminase (AID) deficiency causes the autosomal recessive form of the Hyper-IgM syndrome (HIGM2).
