Two Kindred with the Rare Dominant Inhibitor of the Lutheran and P₁ Red Cell Antigens

Abstract

Two kindred each showing the dominant inheritance of the rare phenotype Lu(a–b–) in the Lutheran blood group system are recorded. The pedigrees illustrate the expected upset in the occurrence of the P₁ antigen in the Lu(a–b–) members. A third Lu(a–b–) propositus of the dominant type was found after testing a further 3,197 donors on the East Anglian panel. The phenotype Lu(a–b–) may not be quite as rare as previously supposed.

The differential expression of the blood group P1‐A4GALT and P2‐A4GALT alleles is stimulated by the transcription factor early growth response 1

“…Mutation in the KLF1 gene has been demonstrated to cause the In(Lu) phenotype, which exhibits suppression of expression of the Lutheran antigens, as well as reduced expression of several other blood group antigens, including P1, on RBCs . Thus it has been speculated that the KLF1 transcription factor might be responsible for the P 1 /P 2 phenotypic formation.…”

Mutations in EKLF/KLF1 form the molecular basis of the rare blood group In(Lu) phenotype

“…Many families exhibiting this phenotype have been studied using serologic methods and apparent dominant inheritance was observed, hence, InLu (inhibitor of Lutheran) to describe the gene responsible. 14,15,33,34 The phenotype is of interest because its characteristic reduced red cell surface expression of antigens from several genetically independent blood group systems (i, P1, and In b ) in addition to Lutheran system antigens suggests abnormality in a pathway common to the biosynthesis of these blood group-active molecules (reviewed in Daniels 35 ). The In b antigen is carried on CD44 and defined by its amino acid sequence.…”

The rare Lutheran blood group phenotype Lu(a–b–): a genetic study

“…In view of the previously described suppression of PI, Aua and i antigens by the In(Lu) gene (('rawford et al 1974; Gibson, 1976), many family members were tested with sera containing these specificities.…”