Prevalence of Bombay phenotype among Bangladeshi 慜� blood group population

Background: The Bombay blood group, a rare type often confused with 慜�, poses a critical transfusion risk, requiring specific compatibility with Bombay (Oh) blood. With a lack of data in Bangladesh, this study aimed to establish a comprehensive database for the rare Bombay phenotype, crucial for transfusion safety. Objective was to determine the frequency prevalence of Bombay phenotype among 慜� blood group individuals. Methods: A cross-sectional study conducted at Bangabandhu Sheikh Mujib Medical University from January 2020 to June 2021 involved, aseptic collection of 3 ml venous blood sample, with forward and reverse blood grouping revealing a 慜� phenotype. Utilizing anti-H lectin resolved discrepancies and confirmed the absence of 慔� antigen in individuals with Bombay blood groups. Blood samples of Bombay phenotype individuals showed the following reactions: anti-A (-), anti-B (-), anti-AB (-), anti-H (-), A cells 4+, B cells 4+, O cells 4+. Results: Among 10,000 individuals with apparent blood group 慜�, 99.97% were identified as 慜� blood type, while only 0.03% exhibited the rare Bombay blood group. ABO and Rh-D blood group frequencies varied over the study period, with B +ve at the highest (28.31%) and AB -ve at the lowest (0.21% to 0.23%). Overall, O +ve had the highest frequency (97.29%), and Bombay blood group was rare, with 慜� dominating at 99.97%. Conclusions: The study identified a 0.03% prevalence of the Bombay phenotype. Due to its potential confusion with 慜� blood group, transfusing 慜� blood to Bombay individuals carries a substantial risk of severe hemolytic reactions, including fatal consequences.

Molecular genetic analysis and predigree of a new FUT1 allele of para-Bombay blood group: a case report / 中国输血杂志

【Objective】 To study the serological and molecular mechanism of a case of para-Bombay blood group caused by 236delG mutation of FUT1 gene and investigate the pedigree. 【Methods】 The ABO, H and Lewis antigens of the proband and her family members were detected serologically, and the ABO blood group was confirmed by gene testing. The FUT1 gene was amplified by PCR and then sequenced. The structure of FUT1 236delG enzyme of the proband was simulated in 3D by SwissModel online server. 【Results】 Serological results showed that the proband was rare para-Bombay ABhm, Le(a-b-). Her father and mother was type A and type B, respectively. The gene results showed that the proband was type AB, while her father and mother was type A and type B, respectively. The sequencing results showed that the proband had 236delG/551_552delAG gene mutation, while her mother had 236delG FUT1 gene mutation, and her father had 551_552delAG FUT1 gene mutation. The 3D simulation of the enzyme structure of the proband FUT1 236delG showed that the translated product was an alpha helix structure with no actual function. 【Conclusion】 The 236delG mutation is a new discovered mutation in FUT1 genotype, with 551_ 552delAG mutation(FUT1* 01N.06 genotype), which can result in the generation of para-Bombay blood group.

Study on molecular mechanism and pedigree investigationof para-bombay blood group caused by rare mutations at position h235 and position h649 of FUT1 gene / 中国输血杂志

【Objective】 To study the molecular mechanism of para-bombay blood group caused by two rare mutation combinations and investigate the pedigree. 【Methods】 ABO and H antigens were detected by serological test, and the ABO blood group was confirmed by gene detection; the FUT1 gene was amplified by PCR and sequenced. 【Results】 Serological results showed that the proband was a rare para-bombay blood Bhm, Le(a-b+ ), and the proband′s parents were both B Le (a-b + ). The sequencing results showed that the proband and his mother had mutation at h235 G→C of FUT1 gene. Proband and his father had mutation at h649 G→T of FUT1 gene. 【Conclusion】 The combination of two rare mutations resulted in the formation of a para-bombay phenotype, which is helpful to clarify the gene polymorphism and genetic heterogeneity of para-bombay phenotype, providing data support and theoretical basis for its blood group identification and safe and reasonable blood use of para-bombay phenotype.

Identification of a rare blood group, “Bombay (Oh) phenotype,” in Bhuyan tribe of Northwestern Orissa, India.

BACKGROUND: Blood group serology plays a vital role in transfusion medicine. The Bombay (Oh) phenotype is characterized by the absence of A, B, and H antigens on red cells and occurs rarely, especially in tribal populations of India. AIMS AND OBJECTIVES: This is a field-based random population study in the Bhuyan tribal community. The study reports three cases of the rare Bombay (Oh) phenotype for the first time in the Bhuyan tribe of Sundargarh district in North-Western Orissa. MATERIALS AND METHODS: Taking informed consent, red blood cells of 836 Bhuyan subjects were tested with three antisera, i.e., anti-A, anti-B, and anti-H (lectin) for forward reaction. Agglutinations of plasma with A, B, and O (H) red cells (reverse reaction) were also tested for the presence or absence of antibodies in the serum. Specialized tests like absorption-elution, titration of naturally occurring antibodies at different temperatures, inhibition of anti-H by O saliva secretor, and determination of secretor status were performed. RESULTS: Three cases of a rare blood group, Bombay (Oh) phenotype, (2 out of 244 Khandayat Bhuyan and 1 out of 379 Paudi Bhuyan from Hemgiri and Lahunipara blocks, respectively) in the Bhuyan tribe of Sundargarh district in North-Western Orissa were detected, giving an incidence of 1 in 122 in Khandayat Bhuyan and 1 in 379 in Paudi Bhuyan, with an average of 1 in 278 among the Bhuyan tribal population. This incidence is high in comparison to earlier studies reported from India. CONCLUSIONS: The practice of tribal and territorial endogamy in a smaller effective populations (for example, there are only 3,521 individuals in Paudi Bhuyan) results in smaller marital distance and inbreeding, leading to increased homozygous expression of rare recessive genetic characters like the Bombay (Oh) phenotype. This study further testifies that the incidence is higher in those states of India where the consanguinity is a common practice.

Identification of the para-Bombay phenotype AB h m / 中国输血杂志

Objective To identify para-Bombay phenotype AB h m. Method ABO and H phenotype were typed. Absorption and elution were performed. Saliva was tested by inhibitory reaction. Direct sequencing was performed and family study was done. Results Proband was typed as rare para-Bombay phenotype AB h mand anti-H was detected in his serum. Family study suggested that the inheritance was autosomal recessive. Conclusion Rare AB h m phenotype was identified and anti-H has been detected in his serum.