Comparison of gene expression in erythroblasts with the In(Lu) phenotype with normal erythroblasts.. Homo sapiens

In order to elucidate the molecular mechanism giving rise to the rare In(Lu) type of Lu(a-b-) blood group phenotype we compared the transcriptome of normal and In(Lu) erythroblasts at different stages of maturation. Many erythroid-specific genes had reduced transcript levels suggesting the phenotype resulted from a transcription factor abnormality. A search for mutations in erythroid transcription factors revealed mutations in the promoter or coding sequence of EKLF in 21 of 24 individuals with the In(Lu) phenotype. In all cases the mutant EKLF allele occurred in the presence of a normal EKLF allele. Individuals with the In(Lu) phenotype have no reported pathology indicating that one functional EKLF allele is sufficient to sustain human erythropoiesis. These data provide the first description of inactivating mutations in human EKLF and the first demonstration of a blood group phenotype resulting from mutations in a transcription factor. Keywords: Time course and cell type comparison. Overall design: Time course study looking at changes in gene expression during erythropoiesis in two cell types: cultured erythroblasts (days 4, 6 and 11) from normal blood donors and from those with the rare blood group In(Lu) phenotype. There are 20 samples in total (10 for each cell type). For each cell type there are 2 samples at day 4 (1 biological replicate, 2 technical replicates, and 4 samples at each of days 6 and 11 (2 biological replicates, 2 technical replicates).