Discordance between ABC blood phenotype and genotype in a domestic short-haired cat.

An adult domestic short-haired feline leukemia virus-infected cat was referred for kidney failure and worsening anemia requiring transfusions. ABC blood typing was performed with an immunochromatographic strip assay at different occasions. Gel column systems were used for the major and minor crossmatching tests, and anti-A and anti-B titers were determined. No discrete A or B bands appeared on the immunochromatographic strips at any time point for the recipient cat. The recipient's plasma agglutinated RBCs from tested type A and B cats. The recipient's RBCs appeared compatible with plasma from 1 type A and 2 B donors, and incompatible with plasma from another type A cat. Genotyping of recipient blood revealed a single homozygous c.179G>T CMAH variant predicting a blood type B. These studies suggest an unusual weak type B or missing all ABC antigens. The latter resembles the exceedingly rare Bombay phenotype in the human ABO blood group system.

[Analysis on Serology and FUT1 Gene of Para-Bombay Phenotype in Zhangzhou Area].

OBJECTIVE: To investigate blood group serological manifestations and molecular mechanism of para-Bombay phenotype. METHODS: The serological manifestations of para-Bombay phenotype was identified by serological assay. Molecular mechanism of para-Bombay phenotype was detected by PCR amplification. RESULTS: Eighteen cases of para-Bombay phenotype were detected through serology and PCR, including 5 cases of Amh, 4 cases of Bmh, and 10 cases of Omh. Eight cases produced anti-HI antibody. CONCLUSIONS: Blood group serology combined with molecular biology can accurately identify para-Bombay phenotype. Special transfusion strategy should be adopted for individual with para-Bombay phenotype to avoid hemolytic reactions.

Overcoming challenges in managing a high-risk pregnancy with placenta previa and newly diagnosed Bombay phenotype.

BACKGROUND: Bombay phenotype is rare and characterized by a lack of H antigen on the surface of red blood cells (RBCs) with naturally occurring anti-H antibodies. The presence of anti-H necessitates the exclusive use of Bombay phenotype RBCs for transfusion. We present a case of a pregnant woman with Bombay phenotype who required urgent cesarean section delivery due to high-risk placenta previa. CASE DESCRIPTION: A 36-year-old G1P0 woman of Indian origin presented at 36 weeks and 4 days gestation for management of a high-risk pregnancy with complete placenta previa. Bombay phenotype was unexpectedly identified on routine testing. Given the rarity of the blood, advanced gestation, and risk of post-partum hemorrhage associated with complete placenta previa and spontaneous labor, prompt strategic planning commenced for a successful delivery. Two frozen allogeneic Bombay phenotype RBCs were available as part of a concise transfusion plan. Intraoperative cell salvage was successfully employed and allogeneic transfusion was not required. CONCLUSION: Management of patients with rare blood types can be extremely challenging and guidance for those presenting later in pregnancy is scarce. Our patient's gestational age precluded the use of well-known effective strategies, including hemoglobin optimization, autologous and directed donation, and procurement of large quantities of rare blood. Rather, our approach utilized multidisciplinary expertise and strategic planning to yield a successful outcome.

A novel FUT1*c.889C>T allele associated with the para-Bombay AB phenotype and computational evaluation of the mutation effect.

BACKGROUND: Mutation in the FUT1 gene can impact the structure and function of α-(1,2)-fucosyltransferase 1 (α2FucT1). To explain the para-Bombay phenotype of a novel FUT1 allele, three-dimensional (3D) modeling and mutation effect analysis of α2FucT1 were performed by bioinformatic tools. MATERIALS AND METHODS: Blood and saliva samples were collected from a patient who was suspected to be a para-Bombay phenotype. H, A, and B antigens were determined with routine serologic methods for those samples. FUT1 and FUT2 coding regions were determined by Sanger sequencing. The novel heterozygous mutation was confirmed by cloning and sequencing. 3D model of mutant α2FucT1 was built by Phyre 2 and the mutation effect was evaluated by Chimera, PROVEAN, and Polyphen-2. RESULTS: Weak H, A, and B antigens were detected on RBCs of the proband and normal quantities of H, A, and B antigens were observed in his saliva. Cloning sequencing showed that the proband carried a novel FUT1 allele (c.889C>T, p.Leu297Phe) and a null FUT1*01N.06 allele. 3D model showed that the p.Leu297Phe variant in α2FucT1 reduced the number of hydrogen bonds and the mutation effect was predicted to be deleterious and possibly damaging, which suggested that the conformation and activity of the enzyme might be significantly damaged. CONCLUSION: A novel missense mutation led to an amino acid variant p.Leu297Phe in α2FucT1, which was a potential cause of the inactivation of the enzyme. Computational evaluation was a convenient and useful approach for the mutation effect analysis of the enzyme.

Identification of two novel FUT1 mutations in people with Bombay phenotype from Iran.

BACKGROUND AND PURPOSE: Bombay and Para-Bombay phenotypes are characterized by FUT1 gene mutation and lack of H antigen expression in red blood cells. ABH antigens are not present in the body secretions of Bombay individuals, while they are expressed in the secretions of para-Bombay. The aim of this study was to investigate the molecular basis of FUT1 and FUT2 genes in Iranians with the Bombay or Para-Bombay phenotype. MATERIALS AND METHODS: ABO phenotype analysis and routine serological tests were performed on 11 people with Bombay and Para-Bombay phenotypes. The coding regions of FUT1 and FUT2 genes were amplified by PCR followed by sequencing. The ABO genotypes were also determined by sequencing exons 6 and 7 of the ABO gene. RESULTS: Serological investigations confirmed the Bombay phenotype in 8 samples and the Para-Bombay phenotype in 3 samples. Family members with the Bombay phenotype had the classic c 0.725 T > G mutation in the FUT1 gene, accompanied by deletion of the FUT2 gene. Other samples had c.653 A>G, c 0.661 C>T, c 0.652 C>G, and c.722 A>C mutations in the FUT1 while FUT2 was silenced by c 0.461 G>A. CONCLUSION: In this research, we identified two novel mutations in the FUT1 gene in individuals with the Bombay phenotype. This and previous works confirm the variety of FUT1 mutations.

Incidental Discovery of a Patient with the Bombay Phenotype.

Bombay phenotype, an exceptionally rare blood type in individuals outside of Southeast Asia, occurs in approximately 1 in 1,000,000 individuals in Europe. This blood phenotype is characterized by the absence of the H antigen on red blood cells (RBCs) and in secretions. As the H antigen is the structure on which the ABO system is built, individuals lacking this antigen are unable to produce A or B antigens and appear as type O on routine ABO phenotyping. H deficiency does not cause ill effect; however, these individuals produce an anti-H alloantibody capable of causing severe acute hemolytic transfusion reactions when exposed to RBCs that express the H antigen. In this case study, we highlight the incidental discovery of a patient with Bombay phenotype in a North American hospital system, expected test results, the immunologic and genetic basis underlying the Bombay and para-Bombay phenotypes, and methods to ensure availability of compatible blood.

A Para-Bombay Blood Group Case Associated with a Novel FUT1 Mutation c.361G>A.

BACKGROUND: Here we report a case of para-Bombay phenotype due to a novel mutation FUT1 c.361G>A p.(Ala121Thr) and a nonfunctional allele FUT1*01N.13(c.881_882delTT) which showed a discrepancy in the routine ABO blood group typing. MATERIALS AND METHODS: The ABO phenotype and the Lewis blood group were typed with serological methods. The ABH antigens in saliva were determined by a hemagglutination inhibition test. The CDS region of ABO, FUT1and FUT2 were amplified with polymerase chain reaction and then directly sequenced. The novel mutation was confirmed by cloning and sequencing. Three-dimensional (3-D) structural analysis of the mutant and wild-type Fut1 were performed by the Chimera software. RESULTS: A, B and H antigens were not detected on the surface of red blood cells (RBCs) by the serological technique, and the B and H blood group substances were detected in the saliva, while the Lewis phenotype was Le(a-b+). Sequencing and cloning analysis showed the presence of a novel FUT1 mutation c.361G>A and a nonfunctional allele FUT1*01N.13(c.881_882delTT). The ABO genotype was ABO*B.01/ABO*O.01.01. The in silico analysis showed that the mutation p.(Ala121Thr) of FUT1did not change the 3-D structure of the whole enzyme but caused a certain amplitude of turnover in the loop region where Ala121 was located. CONCLUSIONS: A novel FUT1 allele (FUT1*c.361G>A) was identified in a Chinese individual with para-Bombay B phenotype. The FUT1c.361G>A mutation may significantly downregulate the expression of H antigens on RBCs by damaging the enzyme conformation.

Two novel FUT1 alleles that cause para-Bombay phenotype in a Chinese individual.

BACKGROUND: Bombay and para-Bombay phenotypes, which arise from gene mutations of α-1,2-fucosyltransferase FUT1, are very rare in Chinese population. A para-Bombay phenotype Chinese individual with two novel FUT1 mutations was reported here. STUDY DESIGN AND METHODS: The peripheral blood and saliva samples of the proband and her family members were collected after informed consent. ABO and H blood group phenotyping was performed by haemagglutination methods. ABO genotype was determined by PCR-SSP kit. A, B, and H antigens in saliva were detected by a hemagglutination inhibition test. Fragments encompassing the full coding region of FUT1 and FUT2 genes were PCR amplified and sequenced. Allelic sequences were validated by cloning and sequencing individual colonies. RESULTS: The serologic reaction results of the proband revealed that A, B, and H antigen were absent on RBCs, but B and H antigen were presented in saliva, and the serum contains anti-H. The proband was assigned as B/O1 by ABO genotyping. Two new heterozygous mutations of FUT1 gene, c.508dupT and c.787A>C, were identified through direct sequencing of PCR-amplified products. TA cloning and sequencing confirmed that two novel mutations were on different alleles. FUT2 gene sequence of the proband is consistent with standard. The other family members of the proband showed normal phenotypes of ABO blood group and their genotypes are consistent with phenotypes. CONCLUSION: Two novel FUT1 alleles, with the previously not reported mutations c.508dupT and c.787C, respectively, are responsible for the para-Bombay phenotype detected in the sample from the proband.

Incidental diagnosis of leukocyte adhesion deficiency type II following ABO typing.

Individuals with the Bombay phenotype (Oh) in the ABO blood group system do not express the H, A, and B antigens but have no clinical symptoms. Bombay phenotype with clinical symptoms has been described in leukocyte adhesion deficiency type II (LAD II), a fucosylation disorder caused by mutations in SLC35C1. Only few LAD II patients have been described so far. Here we describe an additional patient, a 22-year old male, born to unrelated parents, presenting with inflammatory skin disease, periodontitis, growth, and mental retardation, admitted to the department of dentistry for treatment under general anesthesia. Pre-operative routine investigations revealed the presence of the Bombay phenotype (Oh). Genomic sequencing identified two novel triplet deletions of the SLC35C1 gene. Functional investigations confirmed the diagnosis of LAD II. Therapy with oral fucose led to the disappearance of the chronic skin infections and improvements in behavior and attention span.

Immunohematological study of the first pediatric patient with the Bombay phenotype in Medellín, Colombia.

The Bombay (Oh) phenotype is a rare phenotype in which red blood cells lack the H antigen as a result of a point mutation in the H gene. Oh patients are a challenge in transfusion medicine. We present a case of a pediatric patient with the Bombay phenotype who was carried to the emergency department of the Hospital Universitario San Vicente Fundación in Medellín, Colombia. The patient presented gastrointestinal hemorrhage and required transfusion therapy. Pretransfusion and molecular immunohematological analyses identified the Bombay phenotype. The patient was transfused with Oh red blood cells imported to Colombia from the Hematology and Hemotherapy Center of Ceará (Hemoce) in Fortaleza, Brazil. This first case of an Oh individual in Colombia highlights the need to look for donors with rare phenotypes to fulfill the transfusion requirements of the population.

Mutational Analysis of Bombay Phenotype in Iranian People: Identification of a Novel FUT1 Allele.

Bombay phenotype is characterized by lack of ABH antigens on RBCs and in body secretions as a result of mutations in fucosyltransferase 1 (FUT1) and fucosyltransferase 2 (FUT2) genes. The aim of this study was a mutational analysis in Iranians with this phenotype. Serological analyses including ABH and adsorption-elution tests were performed in five unrelated Bombay individuals. ABO genotyping was determined by direct sequencing. The coding regions of FUT1 and FUT2 genes were amplified and sequenced directly or after cloning into suitable vector. A novel missense FUT1 allele was detected (G1051T; G351C). Also four reported FUT1 alleles were revealed. Molecular analysis of FUT2 gene confirmed nonsecretor status in all individuals. This and our previous findings suggest the diversity and population specificity of FUT1 alleles.

Sequence analysis of α-(1, 2)-fucosyltransferase gene in nine Chinese individuals with Para-Bombay phenotype.

BACKGROUND: To analyze the sequence of α-(1, 2)-fucosyltransferase gene (FUT1) in nine individuals with Para-Bombay phenotype. METHODS: Para-Bombay phenotype was defined according to the serologic characteristics and ABO genotypes. The full coding region of FUT1 was amplified, genotype and haplotype were analyzed by direct and TOPO cloning sequencing which was used to discriminate heterozygous mutations of FUT1. RESULTS: These nine individuals were identified as three Para-Bombay A (Ah), six Para-Bombay B (Bh) according to serologic characteristics and ABO genotypes. According to the direct and cloning sequencing results of the full coding region of FUT1, five genotypes and five haplotypes were found in these nine individuals. CONCLUSION: Two complex mutations of FUT1 were discovered, which were h1h547 - 552delAG + 814A > G (c.547 - 552delAG, p.Arg183Argfs ∗ 86; c.547 - 552delAG, p.Arg183Argfs ∗ 86 + c.814A > G, p.lle272Val) and h755G > Ch547 - 552delAG + 755G > C (c.755G > C, p.Arg183Argfs ∗ 86; c.547 - 548delAG, p.Arg183Argfs ∗ 86 + c.755G > C, p.Arg253Pro), the genotype of h755G > Ch547 - 552delAG + 755G > C was reported for the first time, and three kinds of known genotype (h1h1, h3h3, h1h3) were found also in these nine Chinese individuals with Para-Bombay phenotype in the present study. In this way, the FUT1 mutation showed a distinct geographic and ethnic range.

Four Non-functional FUT1 Alleles Were Identified in Seven Chinese Individuals with Para-Bombay Phenotypes.

BACKGROUND: The para-Bombay phenotype is characterized by a lack of ABH antigens on red cells, but ABH substances are found in saliva. Molecular genetic analysis was performed for seven Chinese individuals serologically typed as para-Bombay in Blood Station Center of Ningbo, Zhejiang Province, Ningbo, China from 2011 to 2014. METHODS: RBCs' phenotype was characterized by standard serologic technique. Genomic DNA was sequenced with primers that amplified the coding sequence of α (1, 2)-fucosyltransferase genes FUT1 (or H) and FUT2 (or Se), respectively. Routine ABO genotyping analysis was performed. Haplotypes of FUT1 were identified by TOPO cloning sequencing. Phylogenetic tree of H proteins of different organisms was performed using Mega 6 software. RESULTS: Seven independent individuals were demonstrated to possess the para-Bombay phenotype. RBC ABO genotypes correlated with ABH substances in their saliva. FUT1 547delAG (h1), FUT1 880delTT (h2), FUT1 658T (h3) and FUT1 896C were identified in this study. FUT1 896C was first revealed by our team. The H-deficient allele reported here was rare and the molecular basis for H deficient alleles was diverse as well in the Chinese population. In addition, the FUT2 was also analyzed, only one FUT2 allele was detected in our study: Se357. Phylogenetic tree of the H proteins showed that H proteins could work as an evolutionary and genetic marker to differentiate organisms in the world. CONCLUSION: Molecular genetic backgrounds of seven Chinese individuals were summarized sporadic and random mutations in the FUT1 gene are responsible for the inactivation of the FUT1-encoded enzyme activity.

Blood Diathesis in a Patient of Rare Blood Group 'Bombay Phenotype'.

Bombay blood group or Oh phenotype is a rare autosomal recessive phenotype within the ABO blood grouping system. It occurs due to a mutation in the H gene that produces H antigen on red blood cells (RBCs). Individuals with two mutant H genes lack H antigen on RBCs and have anti-H antibodies in serum. At the time of blood grouping, this blood group mimics O blood group but it shows incompatibility with O group blood during cross matching. Several studies have reported an association of decreased von Willebrand factor (VWF) levels in plasma with ABO blood groups. Here we report a case of a 19-year-old male, who was labelled as Bombay phenotype and later found to have markedly reduced plasma VWF levels.

Molecular basis of Bombay phenotype in Mashhad, Iran: identification of a novel FUT1 deletion.

BACKGROUND AND OBJECTIVES: Bombay phenotype is characterized by the lack of H substance both on red blood cell (RBC) surface and in body secretions. Mutations of fucosyltransferase 1 (FUT1) and fucosyltransferase 2 (FUT2) genes are resulted in this rare phenotype. MATERIALS AND METHODS: Five unrelated patients were tested by hemagglutination and adsorption/elution techniques for the presence of ABH antigens. The saliva specimens were analysed by hemagglutination inhibition method. The exons 6 and 7 of ABO gene were sequenced to determine ABO genotype. The coding fragments of FUT1 and FUT2 were amplified and sequenced by specific primers. RESULTS: Serologic investigation confirmed Bombay phenotype in all individuals. FUT1 molecular analysis revealed a novel large deletion. Also two novel homozygous mutations were detected; one was a missense mutation (392T>C, L131P) and the other a three nucleotide deletion (668_670delACT, Y224del). FUT2 sequencing showed one reported null allele (428G>A, W143X) and one homozygous deletion of FUT2. CONCLUSION: Although FUT2 deletion has been reported, this is the first report of FUT1 deletion. Finding two FUT1 novel alleles in Iranian people is indicative of mutation diversity in this gene.

A rare case of haemolytic disease of newborn with Bombay phenotype mother.

We are reporting a rare case of severe hemolytic disease of newborn (HDN) with Bombay phenotype mother. A retrospective study of a case with severe haemolytic disease of newborn with Bombay phenotype mother was done. Blood grouping, antibody screening, and lectin study was done on the blood sample of the baby and mother to confirm the diagnosis. Hematological and biochemical parameters were obtained from the hospital laboratory information system for the analysis. Blood group of the baby was A positive, direct antiglobulin test was negative. Blood group of the mother was confirmed to be Bombay phenotype, Hematological parameters showed all the signs of ongoing hemolysis and the bilirubin level was in the zone of exchange transfusion. Due to the unavailability of this rare phenotype blood unit, baby was managed conservatively. Anticipating the fetal anemia and HDN with mothers having Bombay phenotype and prior notification to the transfusion services will be of great help in optimizing the neonatal care and outcome.

Transfusion reaction in a case with the rare Bombay blood group.

Bombay phenotype is extremely rare in Caucasian with an incidence of 1 in 250,000. When individuals with the Bombay phenotype need blood transfusion, they can receive only autologous blood or blood from another Bombay blood group. Transfusing blood group O red cells to them can cause a fatal hemolytic transfusion reaction. In this study, we report a case with the rare Bombay blood group that was misdiagnosed as the O blood group and developed a hemolytic transfusion reaction. This highlights the importance of both forward and reverse typing in ABO blood grouping and standard cross-matching and performing standard pretransfusion laboratory tests in hospital blood banks.

Studies on the ABH-Iso-Agglutinins in serum, saliva and milk from mothers with "Bombay" (Oh) phenotype.

BACKGROUND: ABO blood group iso-antibodies are naturally occurring antibodies found in serum and other body fluids. METHODS: Serum, saliva and milk samples from 5 mothers identified as "Bombay" phenotype were tested for ABH-iso-antibodies by routine serological techniques. RESULTS: All the five mothers showed presence of iso-antibodies in the samples tested. Higher titer values in milk than their serum were observed on subjects whose samples were collected in immediate post-partum phase as compared to those whose samples were collected after a lapse of a few months. CONCLUSION: High titer iso-agglutinins against ABH antigens were detected in milk samples besides their presence in saliva as well as serum.

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.