Blood transfusion

Question 1

Genes for ABO Blood Group (O)

Answer 1

Antigens determined by corresponding genes

-O gene is recessive (eg: blood group A individual could have AA genes or OA genes

Question 2

The Rh system (rhesus factor)

Answer 2

-The RhD antigen is the most important
-Can either be RhD positive (D antigen present) or RhD negative (D antigen absent)
Genetics of RhD blood groups:
-D gene codes for D antigen on RBC membrane and is dominant
-d gene codes for no antigen on RBC membrane and is recessive
RhD negative=dd
RhD positive=DD or Dd

Question 3

Genes for ABO Blood Group (A)

Answer 3

Antigens determined by corresponding genes

-A gene codes for enzyme which adds N-acetyl galactosamine to common glycoprotein and fucose stem

Question 4

Genes for ABO Blood Group (AB)

Answer 4

Antigens determined by corresponding genes

-A and B genes are co-dominant (galactose added on some, N-acetyl galactosamine added on others)

Question 5

Genes for ABO Blood Group (B)

Answer 5

Antigens determined by corresponding genes

-B gene codes for enzyme which adds galactose to common glycoprotein and fucose stem

Question 6

Blood Group A

Answer 6

UK Population Frequency: 43%
Antigens: A
Antibodies: anti-B

Question 7

Blood Group AB

Answer 7

UK Population Frequency: 3%
Antigens: A and B
Antibodies: nil

Question 8

Blood Group B

Answer 8

UK Population Frequency: 8%
Antigens: B
Antibodies: anti-A

Question 9

Blood Group O

Answer 9

UK Population Frequency: 46%
Antigens: nil
Antibodies: anti-A and anti-B

Question 10

RhD negative

Answer 10

UK Population Frequency: 15%
Antigens: nil
Antibodies: can make anti-D antibodies (IgG antibodies) after exposure to the RhD antigen (by RhD positive blood transfusion or if female pregnant with an RhD positive fetus)

Question 11

RhD positive

Answer 11

UK Population Frequency: 85%
Antigens: D
Antibodies: nil