Doctors in India discover previously unknown blood type in patient

In the southern Indian state of Karnataka, physicians have made a remarkable discovery: a patient was found to possess a previously unknown blood group. According to reports from TASS, citing The New Indian Express, this groundbreaking finding occurred during preparations for a heart surgery involving a 38-year-old woman from the Kollara district.

The woman’s blood type was identified as O Rh+, the most common blood group worldwide. Yet, none of the available O-positive blood units were compatible for transfusion.

"Employing advanced serological techniques, our team detected that her blood was 'pan-reactive,' incompatible with all tested samples. Recognizing this as a potential case of a rare or unknown blood group, we collected blood samples from twenty family members in search of a compatible donor. Unfortunately, none matched," explained Ankith Matur, a surgeon at Kollara Clinic. Fortunately, the surgery was successful and did not require a transfusion.

The hospital subsequently sent her blood samples to the International Blood Group Reference Laboratory (IBGRL) in Bristol, UK, and the Blood Center in Bangalore, Karnataka’s administrative capital. Over the course of ten months, scientists conducted molecular analyses, ultimately confirming the existence of a previously unidentified blood group antigen, which has been officially named CRIB. This discovery was presented at the 35th Regional Congress of the International Society of Blood Transfusion (ISBT) held in Milan, Italy, in June 2025.

In collaboration with the Indian Council of Medical Research in Mumbai, the Bangalore Blood Center has established a registry of voluntary donors with rare blood groups, with plans to include individuals possessing the newly identified CRIB blood group should they be found in the future.

Several immunologists believe that the emergence of this unknown blood group may be linked to India’s long-standing tradition of consanguineous marriages, which could facilitate the persistence of rare genetic traits within the population.