title: Molecular basis of RhD-positive/D-negative chimerism in two patients.
abstract: This study investigated two patients with Rh chimerism: patient A, a healthy individual, and patient B with myelofibrosis. Flow cytometry studies showed two red blood cell populations of Rh phenotypes R1r and rr at percentages of about 25% and 75% respectively. Normal RhD transcript sequences were found following RT-PCR. Genomic DNA (gDNA) showed normal exon, intron, GATA regions and exon/intron boundary sequences except for a single base change in intron 7 (C --> A) of exon 7 in patient A. The major change found in both patients was the absence of RHD exon 9 DNA in gDNA isolated from peripheral blood. These findings suggest a somatic mutation, probably in a stem cell common to the myeloid lineage of both patients, and indicate that patient A may undergo malignant transformation in the future.
authors.affiliation: Princess Iman Centre for Research and Laboratory Sciences, Department of Haematology, King Hussein Medical Centre, Amman, Jordan.
authors.forename: S S
authors.initials: SS
authors.lastname: Eid
mesh_terms: D000328:Adult; D000368:Aged; D001483:Base Sequence; D046528:Chimerism; D005091:Exons / Q000235:genetics; D005260:Female; D005434:Flow Cytometry; D020869:Gene Expression Profiling; D015894:Genome, Human; D005838:Genotype; D006801:Humans; D038101:Insulator Elements / Q000235:genetics; D007438:Introns / Q000235:genetics; D015464:Leukemia, Myelogenous, Chronic, BCR-ABL Positive / Q000235:genetics*; D008968:Molecular Conformation; D008969:Molecular Sequence Data; D009030:Mosaicism; D009154:Mutation / Q000235:genetics; D010641:Phenotype; D055728:Primary Myelofibrosis / Q000235:genetics*; D020133:Reverse Transcriptase Polymerase Chain Reaction / Q000379:methods; D012204:Rh-Hr Blood-Group System / Q000235:genetics*
chemical_list: D012204:Rh-Hr Blood-Group System; C026410:Rho(D) antigen