Letter to the Editor
Ann Lab Med 2019; 39(6): 599-601
Published online November 1, 2019 https://doi.org/10.3343/alm.2019.39.6.599
Copyright © Korean Society for Laboratory Medicine.
Pitfalls of ABO Genotyping Based on Targeted Single Nucleotide Variant Analysis Due to a Nondeletional O Allele Lacking c.261delG: First Report of ABO*O.09.01 in Korea
Dahae Yang , M.D.1,2 , Boram Kim , M.D.2 , Da Young Song , M.D.2 , Tae Yeul Kim , M.D.2 , Man Jin Kim , M.D.2 , Sung Im Cho , M.T.2 , Hyungsuk Kim , M.D.2 , Moon-Woo Seong , M.D.2,3 , and Sung Sup Park , M.D.2,3
1Department of Laboratory Medicine, Kosin Gospel University Hospital, Busan, Korea; 2Department of Laboratory Medicine, Seoul National University Hospital, Seoul, Korea; 3Biomedical Research Institute, Seoul National University Hospital, Seoul, Korea
Correspondence to: Hyungsuk Kim, M.D.
Department of Laboratory Medicine, Seoul National University Hospital, 101 Daehak-ro Jongno-gu, Seoul 03080, Korea
Tel: +82-2-2072-3500, Fax: +82-2-747-0359 E-mail: firstname.lastname@example.org
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ABO is clinically the most important blood group system. The common O alleles of the
A 10-year-old girl visited Seoul National University Hospital in April 2018 with a one-year history of progressive hearing loss. She was diagnosed as having otosclerosis and was scheduled for laser stapedotomy. During the routine preoperative workup, her mother (whose genotype was previously confirmed to be
The patient's ABO phenotype was serologically determined to be A2B3 with anti-B. The direct antiglobulin test (Bio-Rad, Hercules, CA, USA) was negative (anti-IgG+C3d), and the antibody screening (Bio-Rad) was negative in both panel cells. The ABO group of the patient's father and brother was additionally tested and was serologically typed as A and O, respectively (Fig. 1). Based on the information obtained from the family members, the genotypes were expected to be
Nondeletional O alleles have been predominantly reported in Caucasians . Determining O alleles merely by targeting c.261delG, as in the SNaPshot assay, may lead to misidentification of nondeletional O alleles as A alleles. However, as these genotypes are extremely rare in Asian population , less consideration was given to this possibility.
The phenotypes of individuals with cisAB vary widely . Although our patient expressed A2B3 with anti-B, which is typical for
In conclusion, this case highlights the importance of comparing the serological phenotype and family history when interpreting
Family pedigree of the proband (indicated by an arrow) with
Abbreviation: n/a, not available.
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