What does it mean if a colt is PSSM np?

I am looking for a yearling filly that is listed on All Breed Pedigree as: herda nn, mh nn, hypp nn, gbed nn, pssm np

Anything to fear here?

I'm trying to remember but I think it means it carries one of the alleles and may get PSSM and has a 50% chance of passing it on but don't quote me on it.  

It means he has one copy of pssm type 1. He may or may not be symptomatic. Even though I manage several type 1 horses, I wouldn't buy one that had been tested and was n/P. 
and yes, there is potential for a lot of problems. 

Thank you.  That is what I was concerned about.  

Horse carries it and, from my experience, they will eventually have some symptoms unless you start them on a strict diet and exercise program... Most don't show anything until they are a bit older too so someone saying a young horse is non symptomatic means nothing. It can be managed but it is very frustrating and requires a strict lifestyle for them. I would never own one again. 

These horses can have a productive life, but, they are not for everyone. Being stalled is not their friend. Strict diet and exercise (every day) is required. Most horse owners simply can't fit this commitment into their every day schedule. I would not buy a horse that I knew could develope the problems that are associated with PSSM.

As others mentioned, that horse carries one PSSM gene, and they can be non symptomatic or have issues. 

PSSM is tie up. 

It can be managed by proper diet (which honestly if you feed a low starch and sugar diet once, you will always feed it) but turn out and regular riding are key along with the nutrition part. PSSM 1 is manageable.  PSSM 2 or other variants are alot more difficult.  

PSSM isn't a death sentence by any means... just educate yourself if you decide to go that route.  

I own one with PSSM2 and as mentioned she lives on a special diet and we hit the round pen every day we cannot ride. Definitely not an ideal situation but we raised this one and she is the first one we have had that had it.  Definitely steer clear if possible.

She is a single carrier for pssm-1. That's what my horse is. Unfortunately I was not aware of that when I purchased him as he was not yet registered. If anyone finds themselves in the position of managing a PSSM horse, I can't recommend Equifeast LAM Essentials and they're whole protocol. It has completely changed my horse. But I still would not get another PSSM-1 horse if I could help it.