Weak D phenotype in transfusion medicine and obstetrics: Challenges and opportunities

Table 1 Clinical Interpretation of widespread weak D in distinct groups

Number	Ethnic group	Weak D subtypes	Clinical interpretation	Ref.
1	Caucasian	Weak D types 1, 2, 3	Can be treated as D-positive for RhIG administration and transfusion	[32,34]
2	Asian	Asia type DEL (RHD 1227 G > A)	Appears D-negative in conventional serology but can be treated as D-positive	[34]
3	Iranian	Weak D type 15	Most prevalent; weak D types 1, 2, and 3 account for 15% of cases	[33]
4	Brazilian	Weak D types 1, 2, 3, 4	Most frequent in descending order; presence of both caucasian and arican D variants	[35]
5	Australian	Weak D types 1, 2, 3	Found in 75% of weak D samples; some other types (1.1, 5, 15, 17, 90) showed partial D-epitope profiles	[36]
6	Chinese	Various	45 RHD alleles were identified, including 11 novel variants; 3.5% carried DEL alleles	[37]

RHD: Rhesus D antigen blood group.