Genetic basis of the K phenotype in the Swedish population.

• Abstract in Undetermined BACKGROUND: The absence of all Kell blood group antigens (K0 phenotype) is very rare. K0 persons, however, can produce clinically significant anti-Ku (K5) after transfusion and/or pregnancy and require K0 blood for transfusion. Ten alleles giving rise to the K0 phenotype have been reported: different populations were studied although none from Scandinavia. STUDY DESIGN AND METHODS: Three K0 samples were identified by blood banks in Sweden (Uppsala,Umeå, and Linköping) during a 20-year period. Kell antigen typing was performed with standard serologic techniques by the respective blood banks and K 0 status was confirmed by the International Blood GroupReference Laboratory in Bristol, England. Polymerase chain reaction and DNA sequencing of the KEL coding region (exons 1-19) was performed on genomic DNA. RESULTS:The Uppsala K0 was homozygous for a 1540C>T substitution in exon 13, leading to an immediate stop codon. The Umeå K0 was homozygous for 1023delG in exon 8 that results in a frameshift and a premature stop codon in exon 9. In the Linköping K0, a previously reported mutation g>a at +1 of intron 3 was found. CONCLUSION: Two novel and one previously reported null alleles at the KEL locus are described. The identified nonsense mutations abolish expression of the Kell glycoprotein and are thus responsible for the K0 phenotype in these Swedish families.

Subject headings

MEDICIN OCH HÄLSOVETENSKAP  -- Klinisk medicin -- Hematologi (hsv//swe)

MEDICAL AND HEALTH SCIENCES  -- Clinical Medicine -- Hematology (hsv//eng)

Keyword

Kell

K0

erythrocyte

Blood group antigen

genotype

Publication and Content Type

art (subject category)

ref (subject category)