poor chase (and your little brother of course). I've read of you that chase can be grumpy sometimes and given his age isn't it possible he is doing this because of pain? This can dogs lash out even towards their own people. Hope you find a solution/it won't happen again.
He jumps at my little brother making a very mean bark and bites him when he hugs my mom, play fights with anyone in the house and comes near food. He doesn't do this to anyone else. Well exept he growls when we tell him to do something.
Mmh that sounds more like feeling the need to interfere (handle things). As a precaution can't he be locked away (other room/yard) during meals/friends/play fights or get sent to his mat when he greets/hugs someone.
Your little brother is the youngest right? It almost sounds like chase just doesn't accept him as a "leader" (can't come up with another word at the moment), it is said being consequent helps with this.
But I can't look in your situation or are an expert
Like I said I hope it will all work out for you guys eventually.
something completely different: is Piper staying with you ?