Objective:To analyze the serological and molecular characteristics of rare A el and B el subtypes in the ABO blood group system, and to explore their genotype-phenotype correlation and the potential clinical significance. Methods:From January 1st, 2021, to January 1st, 2025, 289, 815 samples subjected to ABO blood grouping in Henan Provincial People′s Hospital were selected. Samples demonstrating discrepancies between forward and reverse typing, or consistent typing but with abnormal agglutination degree were included. Those affected by underlying diseases, transplantation, age-related and other interferences were excluded. A total of 169 suspected ABO subgroup samples were identified. Sanger sequencing of exons 1-7 and relevant regulatory regions of the ABO gene was performed. Protein structure modeling and mutation effect analysis for two'el′ subtype glycosyltransferases (GTs) were conducted using SWISS-MODEL and PyMOL.Results:A total of 12 Ael, 6 B el, and 2 AB el subtypes were identified. Serological analysis revealed that all 18 A el/B el samples exhibited O phenotype in forward typing. Among them, A el subtypes showed weaker agglutination in reverse typing with A 1c than with Bc (>2+), while the opposite pattern was observed in B el subtypes. The two AB el samples were typed as A in forward typing, with agglutination ranging from 0-1+with Bc in reverse typing. Genetic analysis indicated that AEL.02 (c.646T>A, p.Phe216Ile) was the predominant allele in A el samples accounting for 7 cases. Also, we found an AEL.02-like variant (lacking c.681G>A), AEL.10 (c.963insC), and carrying a compound variant of c.322C>T (p.Gln108Ter) and c.296C>T (p.Thr99Ile). Among B el samples, BEL.03 (c.502C>T, p.Arg168Trp) accounted for 4 cases, one of which lacked the c.297A>G mutation, and novel mutations such as c.145_146dupCG were detected. Structural simulation demonstrated that AEL.02 and BEL.03 disrupted the hydrogen-bonding network within the active centers of GTA and GTB, respectively, and these mutations probably significantly impaired the structural stability of the corresponding GTs. Additionally, the c.296C>T mutation also markedly affected GTA structural stability. Conclusion:A el/B el subtypes are prone to mis-identify routine blood types. Their molecular mechanisms involved a variety of functional variantions, and integrating molecular detection is crucial for achieving accurate sub-typing and transfusion safety.

Objective:To analyze the serological and molecular characteristics of rare A el and B el subtypes in the ABO blood group system, and to explore their genotype-phenotype correlation and the potential clinical significance. Methods:From January 1st, 2021, to January 1st, 2025, 289, 815 samples subjected to ABO blood grouping in Henan Provincial People′s Hospital were selected. Samples demonstrating discrepancies between forward and reverse typing, or consistent typing but with abnormal agglutination degree were included. Those affected by underlying diseases, transplantation, age-related and other interferences were excluded. A total of 169 suspected ABO subgroup samples were identified. Sanger sequencing of exons 1-7 and relevant regulatory regions of the ABO gene was performed. Protein structure modeling and mutation effect analysis for two'el′ subtype glycosyltransferases (GTs) were conducted using SWISS-MODEL and PyMOL.Results:A total of 12 Ael, 6 B el, and 2 AB el subtypes were identified. Serological analysis revealed that all 18 A el/B el samples exhibited O phenotype in forward typing. Among them, A el subtypes showed weaker agglutination in reverse typing with A 1c than with Bc (>2+), while the opposite pattern was observed in B el subtypes. The two AB el samples were typed as A in forward typing, with agglutination ranging from 0-1+with Bc in reverse typing. Genetic analysis indicated that AEL.02 (c.646T>A, p.Phe216Ile) was the predominant allele in A el samples accounting for 7 cases. Also, we found an AEL.02-like variant (lacking c.681G>A), AEL.10 (c.963insC), and carrying a compound variant of c.322C>T (p.Gln108Ter) and c.296C>T (p.Thr99Ile). Among B el samples, BEL.03 (c.502C>T, p.Arg168Trp) accounted for 4 cases, one of which lacked the c.297A>G mutation, and novel mutations such as c.145_146dupCG were detected. Structural simulation demonstrated that AEL.02 and BEL.03 disrupted the hydrogen-bonding network within the active centers of GTA and GTB, respectively, and these mutations probably significantly impaired the structural stability of the corresponding GTs. Additionally, the c.296C>T mutation also markedly affected GTA structural stability. Conclusion:A el/B el subtypes are prone to mis-identify routine blood types. Their molecular mechanisms involved a variety of functional variantions, and integrating molecular detection is crucial for achieving accurate sub-typing and transfusion safety.

Background::Parkinson’s disease (PD) is the second most common neurodegenerative disease after Alzheimer’s dementia. Mitochondrial dysfunction is involved in the pathology of PD. Coiled-coil-helix-coiled-coil-helix domain-containing 2 (CHCHD2) was identified as associated with autosomal dominant PD. However, the mechanism of CHCHD2 in PD remains unclear.Methods::Short hairpin RNA (ShRNA)-mediated CHCHD2 knockdown or lentivirus-mediated CHCHD2 overexpression was performed to investigate the impact of CHCHD2 on mitochondrial morphology and function in neuronal tumor cell lines represented with human neuroblastoma (SHSY5Y) and HeLa cells. Blue-native polyacrylamide gel electrophoresis (PAGE) and two-dimensional sodium dodecyl sulfate-PAGE analysis were used to illustrate the role of CHCHD2 in mitochondrial contact site and cristae organizing system (MICOS). Co-immunoprecipitation and immunoblotting were used to address the interaction between CHCHD2 and Mic10. Serotype injection of adeno-associated vector-mediated CHCHD2 and 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) administration were used to examine the influence of CHCHD2 in vivo.Results::We found that the overexpression of CHCHD2 can protect against methyl-4-phenylpyridinium (MPP+)-induced mitochondrial dysfunction and inhibit the loss of dopaminergic neurons in the MPTP-induced mouse model. Furthermore, we identified that CHCHD2 interacted with Mic10, and overexpression of CHCHD2 can protect against MPP +-induced MICOS impairment, while knockdown of CHCHD2 impaired the stability of MICOS. Conclusion::This study indicated that CHCHD2 could interact with Mic10 and maintain the stability of the MICOS complex, which contributes to protecting mitochondrial function in PD.