Based on the beadchip (b)(4) (performed on (b)(6) 2021), the result for the kidd system depicted as jka-jkb+.Besides, customer performed the sample testing with different molecular platform, which is rt-pcr, it showed jkb - (b)(4).
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Sanger sequencing determine that the individual is homozygous for jkb, jk (a-b+) as reported by hea beadchip.However, the individual is also positive for a polymorphism known for weakening expression of the jkb antigen, jk(b+w).In addition, the individual is also homozygous for a polymorphism which is a known silencing mutation that inhibits expression of jk antigens on red blood cells; therefore, the jk(a-b-) results by serology.This limitation is addressed in the package insert: false positive and/or invalid results may be generated in rare cases where a sample contains examples of molecular events that affect the blood-group antigen expression and phenotypes and the nucleotide changes associated with these events are not explicitly monitored by the assay.Examples include dna-sequence variations including premature stop codon, snp leading to missense change in amino acid, hybrid genes, modifying genes; changes at the rna transcription level including alternative splicing; reduced protein expression, etc.Known phenotypes are knull, jknull (jknull has a prevalence of up to 9% among polynesians), rhnull, rh hybrids, kmod, co (a-,b-), in(lu), lu (a-,b-) and gp hybrids.Presence of a c.179_180del (ser60fs) mutation linked with the fy(b) allele may change the fy(b) antigen expression and lead to a false positive result.
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