On group ‘O’red cells there is no A or B
antigen & the membrane expresses ‘H’
H is a precursor of A & B antigens. A & B
persons have less H substance than O
•Seen in persons with red cells which lack H, A & B antigens &
whose plasma contains anti H, anti A & anti B .
•First discovered in Bombay by Dr .Y . M. Bhende.
•Present in about 4 per million of human population generally.
•In Mumbai it is 1 in 10,000
•More common in India
•179 cases reported in India
•35 to 40 in Mumbai
•12 in West bengal
• When Bombay blood group was first
encountered it was found not to contain
AorB antigen so was thought to be ‘O’ blood
• But these pts could not safely receive normal
‘O’blood group,this proved to be because
they lack ‘H’ antigen.
Arises from inheritance of ‘hh’at H locus.
This genotype do not produce ‘H’carbohydrate
which is the precursor for A&B antigens.
Both parents must carry recessive allele to
transmit this blood type to children.
Pts with this blood group should be transfused
only with this group because hemolysis occurs
if transfused with other groups which may lead
How to detect this blood group?
Can be detected by serum grouping or
This can detect H antibody & test is
conducted with reagent called H lacten.
What if you have this blood group?
All of us should know our blood group.
If it is ‘O’ group make sure it is not Bombay group.
Persons with this group should be cautious & alert.
They should register themselves with leading blood
banks or hospitals so that in case of emergencies
they can be contacted.
It has been proposed to preserve few units of such
group in frozen state[cryopreservation]for acute
As this is a rare blood group, during elective
surgeries ,autologous blood donation can be done.
CASE 1: Kolkata Jan
Hardanpal 68 yrs old renal cell carcinoma patient has
O+ve blood group but he could not be given blood
from normal donors of the same group.
He was diagnosed to have bombay blood group on
• On tracing for donors of this group, in a place called
Bata nagar three members of the same family were
found to have this group.
CASE 2: In PIMS
In PIMS a patient named Mallamma of age 46 yrs was
admitted in Gynecology department with uterine
She was planned to undergo surgery for which
preliminary investigations were done and her Hb. was
found to be 8.4gr/100ml.
When blood transfusion was planned, her blood was
not matching with other O+ve’s and was found to be
having bombay blood group.
As this is a rare group and due to unavailability of
donors, she was treated with parental haematinics.
What do we do if we need bombay
Get all family members and relatives of the patient
tested for this group. it is likely that one or the relative
has this group.
Put up request for the requirement in leading news
Be open to get blood from other cities.
Most effective way is visiting all blood banks in the city
and neighbouring cities.
Finally one thing which all of us can do is spread more
and more awareness about this group in common