The genomic dna sample was sent to (b)(4) for bi-directional sequencing.Sequencing interrogated jk gene exons 4 to 11 and the allele genotype jk*a(588a,1111a), jk*b was identified.Variant jk*c.588 g>a is a published silent variant, p.196 pro/pro (erythrogene database.2016 blood advances vol.1 p.240).Variant jk*c.1111g>a was not previously reported, but this variant encodes an amino acid change, p.371glu>lys.Serology results for this sample is jka negative.Hence, the jk*a(1111a) variant allele is a jk null allele that should be located on jk*a allele preventing jka expression.Id core xt reported a predicted jka+ phenotype, but jk*a(1111a) variant allele, not interrogated by id core xt, is associated with a jka negative phenotype.This false positive result obtained by id core xt is considered a discrepant result and then a malfunction.This case report is covered by limitations number 1 and 10 of id core xt package insert.
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