Will neutering my cat affect his fur length?

I have a longhair cat (a Turkish Angora). He's the first longhair cat I've had. With this breed, the breeder told me the final length of his coat won't come in until he about 2 years old (as in it will continue to get longer until then and then that's as long as it gets); specifically the ruff (like a lions mane) on his neck won't get fuller until he is 2 years the breeder said. Also this breed sheds to a thinner coat during summer and it grows longer in the winter. Will neutering him affect his fur length in any way? Will his fur continue to grow longer until 2 years old like it's supposed to after he is neutered? And will he still get a thinner coat in the summer and fuller coat in the winter like he's supposed to after being neutered or will his fur stay about the same length year round after being neutered?

I'm not an expert, but I've never heard of neutering causing shorter fur.  Have you asked the breeder?

I've heard of neutering causing smaller heads.  I've heard of neutering causing thinner skin.  I had a Siberian that was neutered at five months.  His long fur was very similar to his un-neutered parents.

Maybe someone with more experience can answer.

I do not see how hormones, or lack of them, can have an effect on genes, so I would say, no to both questions.  It depends on his individual genes as to how long his coat will eventually be.  And it depends on the genetics of his breed as to how much his fur will thin in summer and increase in winter.  I believe that all cats shed their winter warmth in summer and regrow it every winter to a greater or lesser degree, so I truly expect him to be no different.  He will almost certainly gain weight, however, so watch out for that and reduce his food accordingly.  

I have a long haired ragdoll cat, who was neutered at 3 months old (2lbs +), and he is incredibly fluffy, and a wee bit squidgy   

Thank you. I wasn't sure if neutering him would affect how long his fur grows to be. I know the stopping of hormones affects other things like size but I didn't know if it would affect his fur length.

Yeah, I was overgeneralising when I said that hormones have no effect on genes, because growth can indeed be effected but only if neutering or spaying is done at too early a stage.  And I believe that it is very rare.  But I'm 99.99% certain that hair length and growth patterns are not effected.  

I think you can relax and look forward to his beautiful long coat, with added oomph in the winter   

I have never heard of it; but if you do get an answer from the breeder or another expert please let us know! I'm really curious!

My mother has a half maincoon (the result of an oops litter from a breeder my aunt knows). She was spayed young and gets very full and fluffy in the winter and sheds her mane in the summer.  

It may appear to affect it, but not in the way I think you are worried about.  (I speak for the Persian perspective) My boys that are neutered have glorious coats, mostly because they don't have the hormones. A whole male, during breeding season, never has as good of a coat as a neuter. The genes for good coat are there, it is just that the hormones make them restless and the coat gets damaged. Unless you are a breeder I strongly advise neutering. Stops you from having to deal with whole male problems.