Rare disease

{
  "id": "MLC-T-ONC-007220",
  "term": "Rare disease",
  "field": "Oncology and biomedicine",
  "definition": "A disease that affects fewer than 200,000 people in the United States. There are about 7,000 rare diseases. An estimated 25 million to 30 million Americans are living with a rare disease. The cause of many rare diseases is unknown, but they are often caused by changes in a person’s genes or chromosomes. Rare diseases are often more difficult to diagnose and treat than the more common diseases. Also called rare disorder.",
  "synonyms": [
    "rare disorder"
  ],
  "references": [
    "NCI Dictionary of Cancer Terms"
  ],
  "url": "https://mlchart.com/terminology/oncology/rare-disease/"
}