Molecular genetic analysis of the Japanese amorph Rhnull phenotype

Department of Legal Medicine and Human Genetics, Jichi-Medical School, Tochigi Japan
Transfusion (Impact Factor: 3.57). 04/2002; 40(5):617 - 618. DOI: 10.1046/j.1537-2995.2000.40050617.x
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    ABSTRACT: BACKGROUND: The absence of expression of C/c and E/e antigens has been associated with rare variant RHCE alleles, referred to as silent RHCE alleles, classically identified among individuals with a rare D- - or Rh(null) phenotype. This work reports on different molecular mechanisms identified in three novel silent RHCE alleles. STUDY DESIGN AND METHODS: Samples from D- - or Rh(null) individuals and their family members, from families for whom Rh phenotype and/or serologic data were unexplained by inheritance of conventional RH alleles, were analyzed. Genomic DNA and transcripts were tested by sequencing analysis. RESULTS: The first silent allele was a RHCE*cE allele carrying an intronic IVS3+5G>A mutation. The second was a RHCE*ce allele carrying an intronic IVS7-2A>G mutation, whereas the third was a silent RHCE*ce allele carrying a 5-bp deletion (Nucleotides 679-683) in Exon 5. CONCLUSION: In addition to hybrid alleles and nucleotide deletion, intronic mutations may be associated with the nonexpression of RhCE antigens. Regarding the RH system, silent alleles may not be investigated among D- - or Rh(null) individuals only. Rh phenotype and/or serologic data unexplained by inheritance of conventional RH alleles should lead to molecular investigations.
    Transfusion 12/2012; · 3.57 Impact Factor
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    ABSTRACT: Lack of Cc and Ee expression is associated with either hybrid alleles in which regions of RHCE are replaced by RHD or nucleotide deletion(s) in RHCE. The former have been found as D- - phenotypes, and the latter as Rh(null) when accompanied by deletion of RHD. We investigated RH in eight samples, three presenting as D- -, whose c-E- red blood cell (RBC) typing was discordant with the RHCE genotype that predicted c+E+. Serologic and molecular testing was performed by standard methods. CASES AND RESULTS: RBCs from Patient 1 were D+C-E-c+e+(w) but DNA testing predicted E+. RBCs from Patients 2, 3, and 4 typed as D+C-E-c-e- but DNA testing predicted c+E+. All had alloantibodies strongly reactive with all RBCs tested except D- - and Rh(null). Patient 5 had anti-c and anti-E but DNA testing predicted she was c+E+. RBCs from three donors typed D+C+E-c-e+ with DNA testing predicting c+E+. All had RHCE*cE with deletion of nucleotide 907C in Exon 6 predicted to cause a premature stop codon at Amino Acid 303 (Leu303Stop). HphI polymerase chain reaction-restriction fragment length polymorphism was used to confirm the deletion and to screen 100 Hispanic, 100 Caucasian, and 100 African American donor samples. One additional example was found. A novel allele, RHCE*cE 907delC (ISBT provisional designation RHCE*03N.02), silences c and E and in the homozygous state resulted in a D- - phenotype and production of anti-Rh17. All eight probands were Hispanic. The allele is associated with discrepant molecular typing, with an approximate frequency of 0.005 in Hispanics.
    Transfusion 04/2011; 51(10):2142-7. · 3.57 Impact Factor
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    ABSTRACT: The red cell membrane has long been the focus of extensive study. The macromolecules embedded within the membrane carry the blood group antigens and perform many functions including the vital task of gas exchange. Links between the intramembrane macromolecules and the underlying cytoskeleton stabilize the biconcave morphology of the red cell and allow deformation during microvascular transit. Much is now known about the proteins of the red cell membrane and how they are organised. In many cases we have an understanding of which proteins are expressed, the number of each protein per cell, their oligomeric state(s), and how they are collected in large multi-protein complexes. However, our typical view of these structures is as cartoon shapes in schematic figures. In this study we have combined knowledge of the red cell membrane with a wealth of protein structure data from crystallography, NMR, and homology modelling to generate the first, tentative models of the complexes which link the membrane to the cytoskeleton. Measurement of the size of these complexes and comparison with known cytoskeletal distance parameters suggests the idea of interaction between the membrane complexes, which may have profound implications for understanding red cell function and deformation.
    Biochemistry and Cell Biology 04/2011; 89(2):200-15. · 2.35 Impact Factor