Serology and molecular genetic analysis of two unrelated individuals with the same novel CisAB blood type.

OBJECTIVE

This study aims to report two unrelated individuals with the same novel CisAB blood type and confirm this rare blood type using a comprehensive approach that combines serological and molecular biology techniques.

METHODS

Peripheral blood samples were collected from two patients and their family members. ABO blood typing and antibody detection were performed using conventional tube methods. Molecular biology techniques were employed to amplify and sequence the 6th and 7th exons of the ABO gene, with reference to gene mutation databases provided by NCBI and ISBT.

RESULTS

The genotypes of the two unrelated individuals were identical and were confirmed as a new genotype through ISBT gene database comparison. Serological testing results showed different antigen reaction patterns, especially in terms of reverse typing. Gene sequencing identified a series of mutation points, and both unrelated individuals and one of their daughters had mutations at 297 A>G, 526 C>G, 657 C>T, 703 G>A, 803 G>C, and 930 G>A. According to the comprehensive results from The Blood Group Antigen Gene Mutation Database provided by NCBI, the genotype was determined as Bw37. However, based on the results from Names for ABO (ISBT 001) blood group alleles v1.1 171023, the sequencing results indicated a novel mutation combination not found in the ISBT database. Considering the serological reactions of all three individuals, the final determination was CisAB.

CONCLUSIONS

This study confirmed the novel CisAB blood type in two individuals through the comprehensive application of serology and molecular biology techniques. The identified gene mutation points were not recorded in known databases, emphasizing the uniqueness of CisAB blood types. This research provides important insights into the genetic basis of ABO subtypes and the characteristics of CisAB blood types, and the relevant results have been submitted to the ISBT website for further research.