A Case of Weak D Serologic Phenotype

Area of Science:

• Immunogenetics
• Transfusion Medicine
• Maternal-Fetal Medicine

Background:

• Rh D alloimmunization is a significant concern in Rh D-negative individuals, particularly during pregnancy.
• Standard Rh D blood typing aims to prevent alloimmunization by identifying Rh D-negative status.

Observation:

• A case of discordant and weakly positive Rh D blood typing results in a pregnant patient was observed.
• Confirmatory genetic testing identified a weak D phenotype.

Findings:

• Genetic variants of the Rh D gene can lead to variable and discordant blood typing results.
• Weak D phenotypes may be clinically managed as Rh D-positive, contrary to initial typing.

Implications:

• Misclassification of Rh D status due to genetic variants can result in unnecessary Rh D immunoglobulin administration.
• Rh D genotyping is crucial for accurate classification of Rh D variants, especially when discordant results are observed.