Chinese doctors discover new genetic sequence behind extremely rare blood type

The rare P blood type has a frequency lower than one in a million

Medical professionals in China’s Jiangsu province have uncovered the genetic sequence behind a rare case of type P blood group – even rarer than the subtypes such as “dinosaur blood” or “panda blood.”

According to People’s Daily, the rhesus-negative blood type often referred to as “panda blood” in China, comprises approximately 0.4 per cent of the Chinese population. In comparison, the para-bombay phenotype, known as “dinosaur blood” accounts for about one in 10,000 to one in 100,000.

The Global Times reported that the P blood type occurs even more infrequently, with a prevalence lower than one in a million.

Now, scientists have identified the DNA sequence – nucleotide molecules – behind the rare blood type P in a person with the blood group subtype, Modern Express Post reported on Saturday.

Nucleotides are small molecules that make up DNA and RNA, which carry genetic information.

After further genetic testing, it was confirmed that the newly discovered gene sequence had never been found before.

For people with this rare P blood type, early detection can help prepare better for blood transfusions.

This is especially so at the time of pregnancy as such individuals can only receive blood of the same kind and incorrect transfusion may lead to miscarriages and stillbirths.

The latest discovery of the DNA sequence behind this rare blood group took place during regular tests conducted last year at a hospital in Taizhou, Jiangsu province, South China Morning Post reported, citing a Chinese medical journal.

Cao Guoping, a doctor at Taixing People’s Hospital told the Global Times that the gene sequencing results in this particular case did not align with the known mutations reported for the P group.

Currently, there have been only nine documented cases of the p blood type in China. According to available data, the P blood group system comprises five regular phenotypes: p1, p2, p1k, p2k, and p.

“After passing the examination by experts from the National Center for Biotechnology Information of the United States, the gene of this cis-AB blood group is now officially included and published in the ‘GenBank’ database that has shared it to the world as a new gene,” Zhang Qian, deputy director of the Laboratory of Baoji Central Blood Station, was quoted as saying by Huashang Daily.

“In the case of female individuals with this blood type, the presence of ‘anti-Tja’ antibodies attacking the placenta directly can lead to recurrent miscarriages and stillbirths,” Dr Cao said, referring to the naturally occurring antibody against the P blood group, according to SCMP.