ABSTRACT
Rh system is one of the highly complex blood group systems with many serologically defined Rh antigens. These antigens are expressed by proteins encoded by a pair of highly homologous genes located on chromosome 1. RHCE gene encodes the CcEe antigens, while the RHD encodes the D antigen. RhD is the most important, immunogenic and polymorphic Rh antigen from the clinical aspects [comprising at least 30 epitopes], as it plays a key role in transfusion medicine. Anti-D antibodies remain the leading cause of the hemolytic disease of the newborn [HDN], and antigen D compatible transfusion is a standard practice in transfusion therapy. Partial D lacks one or more D epitopes, and a partial D individual may be immunized on exposure to a normal D positive during blood transfusion or pregnancy. The DVI and DNB variants are the most frequent partial Ds that lack some D epitopes, DVI is usually typed as D negative while DNB is typed as D positive. We have examined 102 genomic DNA samples collected from blood donors expressing D positive [79 samples] and negative phenotypes [23 samples], to detect DVI and DNB variants, and to investigate the molecular basis of Rh negative phenotype. To verify the DVI variant; simplex PCR was used to detect the presence or absence of RHD exon 10/intron 4, while PCR-SSP was used to detect the DNB variant. Three DVI and three DNB samples were detected. The PCR results indicated a deletion of RHD gene in D negative specimens. The results show that the frequency of the DVI phenotype in Palestinians is greater than expected and routine screening for this phenotype should become mandatory for equivocal weak D blood samples