Genetic genotypes follow strict rules

In org-mode, writing: /matA^HMG/ would be incorrect because the superscript 'HMG' should NOT be italics

If however I were to write: /matA/^HMG the result is not what I expected

The only way to get the correct conversion is to write: /matA/ ^HMG, which despite displaying correctly is of course incorrect because of the space between the 'matA' and the 'HMG'

so How can I write: /matA/^HMG in a way that can be properly displayed?

Is this possible?

Thanks

--R