Consider the following three diseases associated with activation-induced deaminase (AID) and indicate whether you think each of them is accompanied by a higher (H) or lower (L) AID activity in the affected cells compared to normal cells. Your answer would be a three-letter string composed of letters H and L only, e.g. LLL.
( ) Burkitt's lymphoma is a cancer of B lymphocytes originating from the germinal center. In this cancer, chromosomal translocations are observed between the immunoglobulin heavy-chain genes and proto-oncogenes (genes whose overexpression can promote cancer), resulting in aberrant expression of the latter.
( ) Diffuse large B cell lymphoma is a cancer of B lymphocytes in which, in addition to chromosomal translocations, high mutation rates are observed in many genes including proto-oncogenes.
( ) Hyper IgM syndrome is a genetic immunodeficiency syndrome in which IgM antibodies are produced by B cells at high levels and for extended periods, while levels of IgA, IgE, and IgG antibodies are abnormally reduced.