Du PHENOTYPE - A REVIEW
AbstractDu is the phenotypic term used to denote a weakened expression of the D antigen. Du originally defined as those redcells reacting with anti-D only when a more sensitive indirect antiglobulin test was used. Du phenotype can arise fromthree different genetic situations, a) A person may inherit a gene coding for weakened quantitative expression of Duantigen, b) One gene may interact with another to modify and weaken the expression of the D antigen, c) A gene maynot code for the total material that makes up the antigen. The frequency of D'1 antigen is relatively low less than 1%.D" is a poor immunogen, however, accelerated destruction of Du red cells can result if transfused to a person alreadymaking anti-D. Hence Du donor units are currently labelled as Rah positive. Du recipients are labelled as Rah negative.Newborn of Rah negative mother is tested for D & Du and Rh Ig is recommended for mothers of D positive or Dupositive infants in order to prevent potential immunisation. The terms Du variant or partial D'; are recommended whenthere is both a qualitative and quantitative difference noted in the D antigen.
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