MMSC 409 - EXAM 3
2024/2025 Lewis:
Extremely rare occurrence, more in Asian population
Le (a+ b+)
not synthesized on RBC membrane, manufactured by tissue cells and secreted into body fluids
Lewis Ags
can be absorbed onto the RBC membrane from plasma
Le^a and Le^b Ags
____ and _____ are NOT alleles - they are absorbed on and off the RBC membrane
Le^a and Le^b
Le and le are the _____ for Lewis BGS
alleles
Possible Lewis genotypes
LeLe
Lele lele
Lewis Ag depends on the inheritance of what three different genes
Lewis gene (le)
Secretor gene (Se)
ABO genes
Lewis ____ substance is secreted regardless of secretor status
A
this influences the amount of Lewis Ag detected on the RBC membrane
ABO genes
Lewis genes do not directly code for the _____ ____
Lewis Ag
Lewis gene codes for the production of the ___________ _______
L-fucosyltransferase enzyme
this add the L-fucose onto the GLNac of type 1 precursor chains - this addition of L-fucose confers ______ specificity
L-fucosyltransferase enzyme
Le^a
all lewis Ags as soluble substances are readily found in tissues/fluid = _______
glycoproteins
lewis Ag structures RBCs are absorbed from plasma = ______
glyoclipids
Lewis phenotype (name it):
- results from inheritance of Le gene but lack of Se inheritance (non-secretor)
Le (a+b-)
Lewis phenotype (name it):
- frequency of phenotype 22%
- ALL of these individuals are non-secretors (sese)
Le (a+b-)
____ gene is present in 78% of population