A Case of AB Para-Bombay Phenotype with Weak A Antigen Expression.

BACKGROUND: The Para-Bombay phenotype is characterized by H antigen partially or totally deficient on red blood cells and the presence of ABH substances in body fluids. METHODS: A patient with discrepant results in forward and reverse ABO phenotyping was further investigated by serological and molecular methods. RESULTS: Ortho gel and tube results showed weak A antigen expression and weak antibody reacting with A and B cells. Absorption-elution assay detected B antigen, and saliva test confirmed substances H were present. The patient was confirmed as A102B101 and Le(a+b+) phenotype. CONCLUSIONS: These findings suggest that the case is AB Para-Bombay Phenotype (secretor).

Homozygous FUT1 Mutations Causing a Para-Bombay Phenotype: a Pedigree Investigation Report.

BACKGROUND: Para-Bombay phenotype is rare in ABO blood group. We describe FUT1 mutations in a Chinese woman with the para-Bombay phenotype, including her familial inheritance. METHODS: ABO grouping, H antigen detection, absorptionelution test, salivary antigen substance detection, deter-mination of titer of ABH antibody, ABO genotyping, gene sequencing (FUT1,2), blood transfusion compatibility test, and pedigree investigation were performed. RESULTS: The patient was confirmed as group A1 para-Bombay phenotype (Amh) in her family's investigation, revealing her FUT1 gene had c.658C>T (p.Arg220Cys) homozygous mutation and FUT2 gene had c.357C>T homozygous mutation. The patient was provided an appropriate transfusion solution. CONCLUSIONS: A combination of using classical serological methods, gene sequencing methods and pedigree investigation methods can effectively analyze the genetic inheritance of patients with para-Bombay phenotype, increasing their choices of blood transfusion.