Eight novel MICB alleles, including a null allele, identified in gastric MALT lymphoma patients

Abstract
MICA and MICB, as members of the major histocompatibility complex (MHC) class I‐chain‐related genes (MIC), encode stress‐inducible glycoproteins that act as activating ligands for NKG2D and γδ T‐cell receptor‐bearing cells. We here describe the identification of eight novel MICB variants, including a null allele, which were identified in peripheral blood leukocytes of gastric MALT lymphoma patients. Only two of the novel alleles are characterized by point mutations, whereas the other variants display a recombination of known exonic MICB sequences that may be best explained by intragenic conversions. The novel MICB null allele is characterized by a Cytosin (C) deletion in a stretch of four Cs beginning from nucleotide 135 of exon 2 that leads to a premature stop codon (TGA) at codon 66.