Approximately 20% of the white population is homozygous for a recessive point mutation of the FUT2 gene, which leads to the absence of A, B, and H antigen expression, also called the nonsecretor
Recently, the Lewis gene (FUT3) and the secretor gene (FUT2) were cloned (2, 3), and several silent alleles that cause the Lewis-negative (4-9) and the nonsecretor
(1015) phenotypes, respectively, were identified.
Persons with a nonsecretor
gene (FUT2-/-) represent as much as 20% of the European population.
On the basis of a comparison of Ca 19-9 in nonsecretor
and secretor patients, ignoring non-significant differences in tumor stage and grade between the two groups, an examination of Ca 19-9 ratios showed a considerably higher concentration (P <0.
Splenocytes were fused with a nonsecretor
cell line sp2/0 and plated into Dulbecco's modified Eagle's medium containing hypoxanthine, aminopterin, and thymidine with 150 mL/L fetal bovine serum.
Moreover, a non-sense mutation in the fucosyltransferase gene 2 (FUT2), which gives rise to the nonsecretor
phenotype, has been found to provide almost complete protection from experimental and natural NoV infection (2,3).
None of the strains recognized nonsecretor
saliva, which showed that binding to human saliva required A, B, or H motifs.
4 strains have been found to mainly bind saliva from secretors irrespective of blood group (16), although binding to nonsecretor
saliva has been described for VLPs of some GII.
However, after incubation with type B secretor saliva or nonsecretor
saliva, binding was as strong as that observed in positive controls (Table 1).
It's reliable in nonsecretors
and in patients with extramedullary relapse, and it effectively monitors abnormally behaving myeloma, they wrote.
Persons who lack a functional FUT2 gene cannot generate ABH antigens in secretions and, thus, are termed nonsecretors
The latter theory has been supported by the discovery that different norovirus strains may have different histo-blood group antigen (HBGA) binding patterns and that nonsecretors
are not susceptible to infection with certain genotypes or variants (23).