Trisomy

{
  "id": "MLC-T-ONC-008917",
  "term": "Trisomy",
  "field": "Oncology and biomedicine",
  "definitions": [
    "The presence of three copies of a specific chromosome in some or all of the body’s cells instead of the usual two copies. For example, people with Down syndrome have an extra copy of chromosome 21.",
    "The presence of an extra chromosome in some or all of the body's cells. This results in a total of three copies of that chromosome instead of the normal two copies. For example, Down syndrome (trisomy 21) is caused by having three copies of chromosome 21 instead of the usual two copies."
  ],
  "references": [
    "NCI Dictionary of Cancer Terms",
    "NCI Dictionary of Genetics Terms"
  ],
  "url": "https://mlchart.com/terminology/oncology/trisomy/"
}