Blood Group Secretors and H Extras Flashcards
Describe H substance
codes a fucosyl transferase that adds a fucose to the outer most sugar of a type1/2 precursor
Describe Bombay
absence of H ag, still have ABO genes they may transfer to offspring but dont enhibit ag themselves
Autosomal recessive bombay
fails to rx with?
serologically?
what mutation?
hh genotype produces no H ag so no ABO ag can be formed on the rbc
fails to rx with ulex. europeas (H lectin) serologically O
Fut1 gene mutation that silences fucosyltransferase
Describe parabombay
mutation?
all H available…
rbc completely devoid of H ag
exhibit small amounts of A or B ag
mutation to FUT1 that makes fucosyltransferase low reactivity
All H available is converted to A or B by functional acting A/b transferases or FUT2 is functional
Describe A1 phenotype
branched A ag
+ w Anti-A
+ w Anti-A lectin
Describe A2 phenotype
linear A ag
+ w anti-A
- w Anti-A lectin
People who have quantitively less Ag converted from H substances are called?
Subgroup people
Describe the B subgroups
B
very
B: very efficient transferase, detected by B. simp
B3
Mixed field doesnt make anti-b
BX
rxn weak w/ anti-b/anti-a,b
Bm
transferase detectable but doesnt work well
Bel
must be detect by adsorption/elution
Describe what subgroups would look like rxn wise with A
there is NO anti-A2
when a person is negative w AI lectin and positive with Anti-A they are a subgroup
T/F there is a BI lectin
false
Immune stimulated Ab
Anti-D, Anti-Le a
What precentage of the world population demonstrates ABO ag in secretions?
80%
What determins secretor status?
chromosome 19 codes a FUT2 that determins secretor status
Se dominant
Describe Type 1 shapes
carbohydrates on the outside of the cell can be branchy or straight, if they are arranged in a specifc format they are type 1
Type 1
substance attached…
converted
substance attached to soluble secretions in body fluids such as tears/saliva
converted by the same transferases as type 2 chains on rbcs to A or B ags
What causes risky transplants?
carbohydrates in secretions may absorb onto anything
Testing for secretions does?
leads to ABO determinations
ABH ag on RBC
ag made from glycolipids/proteins
Type 2 chains
FUT1 enzyme from H
rbcs/lymphs/enothelial cells
ABH ag soluble secretions
Ag are glycoprotein only
Type 1 chain
FUT2 enzyme produced by Se gene
saliva/tears/bile/milk
FUT1
Hh/HH codes a fucose that is added to a type 2 substance on cells
FUT2
SeSe/Sese codes a fucose that is added to a type 1 substance on secretions
FUT3
LeLe/Lele codes a fucose to the non terminal end of Ag in secretions ONLY
Non secretors
fucose transfer
H ag
Lea have only one fucose transferred, fucose added to make H ag has not been added yet
Lea Ag on RBC
genotype
what hasnt formed
faulty?
non secretor (se/se)
H ag not formed on FUT2
a person who has both ag on rbc has falty fucose made by secretor gene
Leb ag on RBC
secretor (FUT2 added a fucose/FUT3 added a fucose)
people who are Leb + do not make Anti-lea
T/F LW ag can cross the placenta
false
No LW ag on rbc
neg for?
may?
negative for FUT3 (le/le) may secrete ABH ag still
