RHD*DOL1 and RHD*DOL2 encode a partial D antigen and are in cis with the rare RHCE*ceBI allele in people of African descent.
BACKGROUND
Several studies showed in people of African descent the existence of a genetic linkage between RHD alleles encoding a variant D antigen and a given altered RHCE*ce allele. RHCE*ceBI is a rare allele encountered in people of African descent, that encodes a Hr- hr(S) - Rhce protein. Our study shows that RHCE*ceBI appears to be genetically linked to two very similar variant RHD alleles, RHD*DOL1 and RHD*DOL2, and demonstrates for the first time that DOL-2 is a partial D antigen.


METHODS
After finding out an individual with both RHCE*ceBI and RHD*DOL presumed to be in cis, we hypothesized a genetic linkage between those two genes. All individuals (n = 7) known to carry RHCE*ceBI in our laboratory, including the index case, were fully investigated at the serologic and molecular level.


RESULTS
One individual with alloanti-D, being homozygous for RHCE*ceBI and RHD*DOL2, allowed us to confirm the genetic linkage between those two genes, as well as the partial D status of DOL-2. In the six RHCE*ceBI remaining individuals, three were found with RHD*DOL2 and 3 with RHD*DOL1, likely in cis. Three of them made an alloanti-D; one was DOL-1 and two were DOL-2.


CONCLUSIONS
The rare RHCE*ceBI allele appears to be in cis either with RHD*DOL1 or with RHD*DOL2 in people of African descent. DOL-1 and DOL-2 must be considered as partial D antigens. We recommend a systematic search for RHD*DOL1 and RHD*DOL2 in people found to carry RHCE*ceBI and vice versa, especially in patients with sickle cell disease.
Centre National de Référence pour les Groupes Sanguins, Institut National de la Transfusion Sanguine, Paris, France.
Michèle
M
Roussel
Sylvie
S
Poupel
Joëlle
J
Nataf
Geneviève
G
Juszczak
Geneviève
G
Woimant
Agnès
A
Mailloux
Cécile
C
Menanteau
Bach-Nga
BN
Pham
Philippe
P
Rouger
Pierre-Yves
PY
Le Pennec
Thierry
T
Peyrard
D000483:Alleles; D044383:Black People / Q000235:genetics*; D004843:Epistasis, Genetic / Q000502:physiology; D005260:Female; D005787:Gene Frequency; D014644:Genetic Variation / Q000235:genetics / Q000502:physiology; D006801:Humans; D007231:Infant, Newborn; D008297:Male; D011247:Pregnancy; D020033:Protein Isoforms / Q000235:genetics; D012204:Rh-Hr Blood-Group System / Q000235:genetics*; D017422:Sequence Analysis, DNA; D012698:Serologic Tests
D020033:Protein Isoforms; C066468:RHCE protein, human; D012204:Rh-Hr Blood-Group System; C026410:Rho(D) antigen