Possible hereditary disorder (??)

[Secret170193]

One of my hamsters, an umbrous male Syrian, has been with us since birth and we've discovered him to be a little... off compared to his siblings and parents. He's reached full adult size (he's about seven or eight months old) but he's a fair bit smaller than his brother, both in length and muscle mass. He also has very slightly bulging eyes (definitely nowhere near the level of protrusion though) which we've put down to him not quite growing into his eyes.

He also likes to stare off into the distance like he's having an existentialist crisis. The only thing I can think of is that we have a very high success rate in litters and that he could have been a runt that managed to make it due to some extra care.

Just in case it's anything else that I've never heard of before I thought I'd reach out and see if anyone here knows of any disorders that syrian hamsters can get that might cause these symptoms.