Available parameters and response documentation is available here

GET /lookup/rs113488022
HTTP 200 OK
Allow: GET, HEAD, OPTIONS
Content-Type: application/json ;utf-8
ETag: "815e424153abfa464fd9f695bbae95304114001d4b5183f4ecb32679d7d6ce6a"
Vary: Accept

[
  {
    "chromosome": "chr7",
    "alt": "C",
    "ref": "A",
    "pos": 140453136,
    "variant_id": "10190071404531360002",
    "variant_type": "SNV",
    "cytobands": "7q34",
    "publication_counts": null
  },
  {
    "chromosome": "chr7",
    "alt": "G",
    "ref": "A",
    "pos": 140453136,
    "variant_id": "10190071404531360003",
    "variant_type": "SNV",
    "cytobands": "7q34",
    "publication_counts": null
  },
  {
    "chromosome": "chr7",
    "alt": "T",
    "ref": "A",
    "pos": 140453136,
    "variant_id": "10190071404531360004",
    "variant_type": "SNV",
    "cytobands": "7q34",
    "publication_counts": null
  }
]