Scala - Dynamically deserialize json to datastructure

I have searched a lot but not found any answer to my question. Here's what I'm trying to achieve: I can serialize datastructures into a JSON (of my own implementation)

def serializeJSON(data: Any): JSON = {
    data match {
        // should deal with most regular collections
        case t: mutable.Traversable[_] =>
            val ar = new JSONArray()
            t.foreach(x => ar.eltAdd(serializeJSON(x)))
            ar
        case t: immutable.Traversable[_] =>
            val ar = new JSONArray()
            t.foreach(x => ar.eltAdd(serializeJSON(x)))
            ar
        case p: Product2[_,_] => // especially for Map
            val ob = new JSONObject()
            ob.set(p._1.toString, serializeJSON(p._2))
            ob
        case a: Array[_] =>
            val ar = new JSONArray()
            a.foreach(x => ar.eltAdd(serializeJSON(x)))
            ar
        // leafs
        case null => new JSONNull
        case s: String => new JSONString(s)
        case x if x.isInstanceOf[Int] | x.isInstanceOf[Long] | x.isInstanceOf[Double] |
                x.isInstanceOf[Float] | x.isInstanceOf[Short] => new JSONNumber(x.toString)
        case b: Boolean => new JSONBoolean(b)
}

Now I'm trying to deserialize data that were serialized this way. Of course I need to know the type I want to deserialize into, but let's assume that I have it. I need something like:

private def deserializeJSON[T: TypeTag](data: Json): T = ???

Deserializing leafs is pretty straightforward, I think I can manage arrays as well with this question. But I truly have no idea of how to deserialize a JSON into a Map[Int,List[String]] for example. If someone could give me a hint I would really appreciate that!