Gene Relationship
GET /api/genes/NKX2-1/relationships/variant_set?format=api
{
    "data": [
        {
            "type": "SmallVariant",
            "id": "1227"
        },
        {
            "type": "SmallVariant",
            "id": "1231"
        },
        {
            "type": "SmallVariant",
            "id": "1249"
        },
        {
            "type": "SmallVariant",
            "id": "359"
        },
        {
            "type": "SmallVariant",
            "id": "2358"
        },
        {
            "type": "SmallVariant",
            "id": "2364"
        },
        {
            "type": "SmallVariant",
            "id": "3148"
        }
    ]
}