weak D type 4.2.1 (DAR1.1)

Structure

RHD(T201R,F223V,,I342T)[957G>A]

Key changes from standard allele

1025T>C (I342T)
602C>G (T201R)
667T>G (F223V)
957 G>A

ISBT allele designation

RHD*09.01.01
RHD*DAR1.01
RHD*weak 4.2

Nucleotide changes relative to "standard RHD"

c.[602 C>G ;667 T>G ;957 G>A ;1025 T>C]

Amino acid changes relative to standard protein

T201R, F223V, I342T

ISBT group

partial RHD

Phenotype characterization and grouping

Partial D; weak D type; weakened D expression

Haplotype (typical)

cDe

Allele cluster

weak D type 4 cluster

Descriptions

First full publication: 2000 Wagner FF et. al. Blood. 2000 Apr 15;95(8):2699-708. (submitted 1999-08-13)

Serology

Antigen density given for "weak D type 4.2", not specified whether type 4.2.1. or type 4.2.2 The anti-D was an auto-anti-D, but an allo-anti-D was observed for weak D type 4.2.2 carrying same protein structure Wagner FF et. al. Blood. 2000 Apr 15;95(8):2699-708.: anti-D observed
754 â?? 1,542 antigens/cell (2 samples, 22 to 50 antibodies, 12 laboratories) Rhesus Index 0.33 â?? 0.78 (2 samples, 22 to 50 antibodies, 12 laboratories) weak D type 4.2 subtype not specified Flegel WA et. al. Transfus Clin Biol. 2002 Jan;9(1):33-42.
Rhesus index 0.57. Data given for "weak D type 4.2", not specified whether type 4.2.1. or type 4.2.2 The anti-D was an auto-anti-D, but an allo-anti-D was observed for weak D type 4.2.2 carrying same protein structure Wagner FF et. al. Blood. 2000 Apr 15;95(8):2699-708.: anti-D observed

Observations

Brazil (general): 14 of 369 samples with atypical D expression Arnoni CP et. al. Transfusion. 2014 Apr;54(4):962-9. doi: 10.1111/trf.12557. Epub 2014 Feb 28.
African ancestry (general): Wagner FF et. al. Blood. 2000 Apr 15;95(8):2699-708.

Additional comments

This allele was first described as weak D type 4.2.1. Many years later, it was shown that it represented the "true" structure of the samples initially assigned to the DAR1 allele.

Last update: 2018-02-19 (yyyy-MM-dd)