If the first initial and surname make a word..

[mammamiaaaaa]

Is this a problem? If it is nothing derogatory...

I can't see why there's a problem with it :)

DS1's initials make a word. He is 9 and it hasn't been a problem so far.

My DD's first initial and surname make a word, as did her Grandmother's and does her Aunt. They all seem to be unscathed by the experience so far. Bizarrely, DD learnt to spell the word that it makes quite a long time before she mastered the spelling of her surname!

My dh and my dd both have this. As long as the word isn't derogatory, I don't see it as an issue.

It's not great if you can spell a rude word. Travis Hitchings. Ewan Kilmer etc. Kids will spot the word!

My maiden name did this. It was quite an unusual word. Never caused an issue.