Halloween special : A blood group named after a place ? Bombay blood group it is !

It's been months that I haven't dedicated my time to write an article for my blog. So considering my gap in writing and upcoming Halloween, I tried to write an article on Blood groups.

We all known few diseases and surgeries that are named after people who either discovered them or invented them. But have you ever heard about a blood group that is named after a place ? This article is on the 'Bombay (hh) blood group' that is named after a place Bombay (formerly), which is now Mumbai, in India, a land of diversity (and my very own birthplace and favorite hometown).

What makes Bombay blood group so rare ?

Bombay blood group, also known as hh blood group, is a rare blood group. It is named after Bombay as it was first discovered in Bombay, India, in 1952. It is so rare that 4 cases can be found among 1 million people, i.e-0.0004%.

Every blood group cells either have antigens or lack antigens, owing to which they are known as Rh+ve or Rh-ve. (Rh is Rhesus factor, named after experiments were originally conducted in Rhesus monkeys.)

The phenotypes of this hh blood group lack H antigen on the red cell membrane and have anti-H in the blood serum. A, B or H antigen is not present on the surface of their red cells or other tissues.

Biochemistry and genetics underlying it :

Biosynthesis of the H, A and B antigens involves glycosyl transferase enzymes that transfer monosaccharides. The resulting antigens are oligosaccharide chains, that are attached to lipids and proteins that are anchored in the red blood cell membrane. H antigen acts as an intermediate substrate in the synthesis of ABO blood group antigens. Individuals who lack the H antigen do not suffer from deleterious effects, other than times when they need a blood transfusion, considering the rare occurences of this blood group, which makes it difficult to procure blood of hh type amidst emergencies. hh genotype, i.e-2 recessive alleles of the H gene occurs when individuals whose bodies don't produce H carbohydrate mate.

Although having a hh blood type is rare, it is not fatal as long as the condition of the patient isn't serious and immediate blood transfusion isn't required.

As rare as this blood group is, as rare and beautiful is the city it is named after.

To end this article with an appreciation of natural mechanisms in the human body, that allowed a few genes to work in a way that such a rare blood group could exist, the more I read about such cases, the more I fall in love with science.

Hoping you fall in love with it too !

Happy Bloody Halloween :P

- Rachna Jadhav

@theresilientresearcher