Screening for DEL phenotype in RhD negative Indians

Area of Science:

• Hematology
• Genetics
• Immunology

Background:

• The DEL phenotype is a weak RhD variant, often misidentified as RhD-negative, potentially causing transfusion complications.
• Molecular methods are crucial for identifying DEL variants, prevalent in East Asian and Caucasian populations.

Purpose of the Study:

• To screen RhD-negative Indian individuals for the two most common DEL mutations: RHD(K409K) and RHD(M295I).
• To assess the prevalence of these specific DEL alleles in the Indian population due to limited existing data.

Main Methods:

• Serological testing for Rh antigens (C, c, D, E, e) and DEL phenotype confirmation using adsorption-elution.
• Molecular analysis using Polymerase Chain Reaction-Sequence Specific Priming (PCR-SSP) to detect RHD(K409K) and RHD(M295I) alleles in 900 RhD-negative individuals.

Main Results:

• Rh phenotyping confirmed 153 r'r, 10 r''r, and 737 rr phenotypes among the 900 participants.
• All samples tested negative for RhD antigen by adsorption and elution.
• Neither the RHD(K409K) nor the RHD(M295I) DEL alleles were detected in the study cohort.

Conclusions:

• The two common DEL alleles screened are rare in the studied Indian RhD-negative population.
• Further comprehensive studies with larger sample sizes are recommended to investigate other potential DEL mutations in India.