Correct way of reading nomenclature of polymorphisms - (Jun/09/2014 )

Hi all, 

I just wonder, what is the correct way of reading nomenclature of polymorphisms.

For example, i have this polymorphism: TNF -308G>A

Do I pronounce it as:

- TNF minus three zero eight G to A polymorphism

- TNF minus three zero eight GA polymorphism

- TNF minus three hundred and eight G to A polymorphism

That appears to be a promoter polymorphism (that's what the "-" indicates) so it would be referred to as minus.  How you say the number is up to you, and  usually it would be "G to A" for the substitution.

Thanks a lot!

I would say "G to A substitution at the position minus 308 from translation start (or ATG) of TNF gene". That's what it is.

If it's in the promoter or not, that depends.

See HGVS nomenclature.

BTW "Polymorphism" is generaly some substitution, that is polymorphic in the population, so there are more than one "common" variants.  It's also used when meaning "without effect", though also term "functional SNP" exists, that indicates a "polymorphism" with a function".

"Mutation" is sometimes used when decribing a rare, functional variant, but it's not prefered.

"Substitution" or "sequence variant" is more neutral.