Site-Specific Factor 10

18q Loss of Heterozygosity (LOH)


**Note 1:** This is a special molecular diagnostic test performed on tumor tissue to identify loss of genetic material normally found on the long arm of one of the patient's two copies of chromosome 18. A normal cell will contain two complete copies of each chromosome, one from each parent, and this normal state is termed heterozygous. Loss of heterozygosity (LOH) is an abnormal state reflecting damage to the chromosome that may mean that normal tumor suppression functions cannot take place. **Note 2:** Other terms for LOH include gene deletion and allelic loss.




NAACCR #2864
Code Description
010 Test positive for loss of heterozygosity (LOH)
020 Test negative for LOH; normal heterozygous state
030 Undetermined if LOH positive or negative
988 Not applicable: Information not collected for this case
997 Test ordered, results not in chart
998 Test not done (test not ordered and not performed)
999 Unknown or no information
Not documented in patient record