Jk null alleles in two patients with anti-Jk3

• Published in: Blood transfusion = Trasfusione del sangue Vol. 19; no. 3; p. 237
• Main Authors: Allhoff, Wolfgang, Weidner, Lisa, Lindlbauer, Nadja, Grüner, Lydia, Libisch, Manuel, Schistal, Elisabeth, Jungbauer, Christof
• Format: Journal Article
• Language: English
• Published: Italy 01-05-2021
• Subjects: Aged, 80 and over; Alleles; Female; Gene Deletion; Genotype; Humans; Kidd Blood-Group System - genetics; Membrane Transport Proteins - genetics; Middle Aged; Mutation; Polymorphism, Genetic; Urea Transporters
• ISSN: 2385-2070

As of publication, a total of 41 null alleles have been acknowledged by the International Society of Blood Transfusion (ISBT) to cause the rare Jk
phenotype, but none have been discovered in Austria thus far.
Two patients with anti-Jk3 were serologically identified by a positive antibody screening and typed as Jk(a-b-). The initial genotyping using an SSP-PCR method for the common 838A/G polymorphism indicated a JK*02/02, or JK*01/02 genotype, respectively. To find the disruptive mutations, Sanger sequencing was performed and results were compared to the reference sequence. The patient's antibodies were characterized with a monocyte monolayer assay (MMA) for their potential clinical significance.
Three novel null-mutations of the SLC14A1 gene were found in two patients. Patient 1 was homozygous for a 10bp deletion in exon 4 (c.157_166del on JK*02). Testing of her family members revealed Mendelian inheritance of the deletional allele. The other patient was compound heterozygous for two mutations: one allele carrying a single base deletion in exon 4 (c.267delC on JK*01) and the other a splice site mutation in intron 3 (c.152-1g>a on JK*02). The MMA results suggest high clinical significance of the anti-Jk3 in both patients.
The detected mutations led to Jk
phenotypes and are the first description of JK
alleles in the Austrian population.