CHEN Bile,HONG Junying,LIU Mengzao, et al. Identification and analysis of a rare clinical case with AB and para-Bombay phenotype[J]. JOURNAL OF WEZHOU MEDICAL UNIVERSITY, 2022, 52(6): 494-497.
Abstract：Objective: To explore serological identification of blood type and genetic basis of a proband with para-Bombay AB blood type. Methods: ABH and Lewis antigens on the red blood cell (RBC), RBC irregular antibodies in plasma and the ABH blood group substances in saliva were detected by standard serologic techniques.Exons 6 and 7 of the ABO gene and exons of FUT1 and FUT2 genes were subjected to direct sequencing, and PCR amplification products were compared with the gene reference sequence to analyze the mutation sites by blast. Results: Serologic reaction results revealed that A and Leb antigens were present on the surface of RBCs from the proband, but B, H and Lea antigens were absent. A, B and H antigens were present in saliva, and the serum contained anti-H IgM antibody. The proband was proven to be a *A1.02/*B.01-type ABO gene carrier,DNA sequencing revealed that she has harbored c.551_552delAG and c.881_882delTT, and c.357C>T compound
heterozygous variants of the FUT1 gene, and c.357C>T homozygous point mutation was revealed in FUT2 gene. Conclusion: Heterozygous deletion of FUT1 genes were responsible for the Para-Bombay phenotype found in secreted AB type-proband. The para-Bombay blood type ABmh phenotype of the proband may be attributed tothe FUT1 gene compound heterozygous variants.
