Identification of three MICA alleles in the genotype of a patient with chronic lymphocytic leukemia.

Major histocompatibility complex (MHC) class I-related chain A gene (MICA) sequence-based genotyping (SBT) was attempted on a peripheral blood sample collected from a patient evaluated for hematopoietic stem cell retransplant. The electropherogram pattern of MICA SBT indicated the possibility of carrying more than two MICA alleles. Subsequent cloning and sequencing of the polymerase chain reaction products revealed the presence of three distinct MICA alleles: MICA*008:01/:04 (A5.1), MICA*007:01(A4), and MICA*002:01 (A9) in the genotype of this patient. The origin of the third extra MICA allele could not be determined and would require MICA genotyping information from other family members, which is unavailable.