What is 'CRIB'? Know about never-seen blood group detected in 38-year-old Indian woman

A 38-year-old woman from the Kolar district in Karnataka has been identified as the first person in the world with a previously unknown and exceptionally rare blood group, according to a media report. Medical professionals have stated that if she requires a blood transfusion, she would need to donate her own blood beforehand, as no other individual possesses the same unique blood type. The case was referred to the Advanced Immunohematology Reference Lab at the Rotary Bangalore TTK Blood Centre after initial attempts to find a match proved unsuccessful.

What is CRIB?

According to a report by The Hindu, experts at the lab observed an unusual reaction between her blood and every sample tested, indicating a unique antigen never before documented. Further testing of her family members also failed to yield a match. The discovery originated when she was admitted to R.L. Jalappa Hospital in Kolar in February last year for heart surgery, with her known blood type being O Positive, a relatively common type.

During the course of her treatment, the woman's blood proved incompatible with all others. Even blood samples from her family members were not a match. Subsequently, doctors forwarded her samples to the International Blood Group Reference Laboratory (IBGRL) located in Bristol, UK.

Following a comprehensive 10-month analysis utilising molecular techniques, the laboratory confirmed the presence of a novel antigen in her blood. This new antigen has been officially recognized as part of the Cromer (CR) blood group system.

Why the blood group has been named CRIB?

The antigen has been named CRIB – with "CR" representing Cromer, and "IB" indicating India, Bengaluru.

What are the side effects of this blood group?

The discovery was presented at an international blood transfusion conference in Milan, Italy, on June 4, 2025. Medical professionals have emphasized that if she requires another transfusion, she cannot depend on blood donations from others. For scheduled surgeries, she may need to increase her own hemoglobin levels and store her blood in advance, a procedure known as autologous transfusion.

The Rotary Bangalore TTK Blood Centre, in collaboration with other organizations, has initiated a ‘Rare Blood Donor’ program to support individuals with uncommon blood types. They have already identified 21 rare donors from a pool of over 2,000 individuals tested.