This gene encodes a RNA-editing deaminase that is a member of the cytidine deaminase family. The protein is involved in somatic hypermutation, gene conversion, and class-switch recombination of immunoglobulin genes. Defects in this gene are the cause of autosomal recessive hyper-IgM immunodeficiency syndrome type 2 (HIGM2). [provided by RefSeq, Feb 2009],catalytic activity:Cytidine + H(2)O = uridine + NH(3).,cofactor:Zinc.,disease:Defects in AICDA are the cause of autosomal recessive hyper-IgM immunodeficiency syndrome type 2 (HIGM2) [MIM:605258]. HIGM2 is characterized by normal or elevated serum IgM levels with absence of IgG, IgA, and IgE, resulting in a profound susceptibility to bacterial infections. HIGM2 causes the absence of Ig class switch recombination (CSR), the lack of Ig somatic hypermutations, and lymph node hyperplasia caused by the presence of giant germinal centers.,function:RNA-editing deaminase involved in somatic hypermutation, gene conversion, and class-switch recombination. Required for several crucial steps of B-cell terminal differentiation necessary for efficient antibody responses.,online information:AICDA mutation db,similarity:Belongs to the cytidine and deoxycytidylate deaminase family.,tissue specificity:Strongly expressed in lymph nodes and tonsils.,
