Ummm...HUGO does NOT appear to concur with your example even in the link you provided. In your link, as well as the one I provided earlier, vascular endothelial growth factor A shows VEGF for previous symbols and VEGF-A or VPF for aliases and not vegf or vegf-a. Or are you referring to people writing "Vascular Endothelial Growth Factor" instead of "vascular endothelial growth factor?" If so, I'd need to say that I have NEVER seen someone write "Vascular Endothelial Growth Factor," capitalizing each initial letter, but if he did, it would probably be meant to emphasize the letters used for the acronym, rather than due to misunderstanding the rules for capitalization.
In a side note, I might add that capitalization of these acronyms may have arisen from the use of word processing software. As we all know, writing a scientific manuscript in Microsoft Word can be quite annoying, as Word attempts to \"fix\" various scientific words or underline them mercilessly; however, this is not the case when words are written as acronyms (in all capital letters). Thus, it makes life easier to write in caps. Just a theory, though.
Edited by Dr Teeth, 21 July 2009 - 10:29 AM.