None barking german sheperd

Question
Hello, I'm about to purchase a 6 month old german sheperd but I was told that the dog doesn't know how to bark. Is this possible for a 6 month dog to not know how to bark? Should I be concerned of some type of illness the dog has?

Thx in advance

Answer
I never heard of a disease causing a dog not to be able to bark.  I guess it could have been born with defective vocal chords.  Most German Shepherds are fairly vocal.  I guess she could just not bark much.  If a vet hasn't looked at the problem, you might make that conditional to the sale.  

The 9 month old Lab I have now seldom barks, not even to come in.  It is a wonder she didn't freeze to death last winter when I would forgot about her and leave her out for hours while busy answering questions.  other than that, I am not sure it is important to have a dog that barks.  It certainly reduces the chances of a barking problem.