NAACCR Item #3801: Chromosome 1p: Loss of Heterozygosity (LOH)

Item # Length Source of Standard Year Implemented Version Implemented Year Retired Version Retired
3,801 1 NAACCR 2018 18

NAACCR XML: Tumor.chromosome1pLossHeterozygosity


Chromosome 1p: Loss of Heterozygosity (LOH) refers to the loss of genetic material normally found on the short arm of one of the patient's two copies of chromosome 1. Codeletion of Chromosome 1p and 19q is a diagnostic, prognostic and predictive marker for gliomas and is strongly associated with the oligodendroglioma phenotype.


Chromosome 1p: Loss of Heterozygosity (LOH) is a Registry Data Collection Variable in AJCC. It was previously collected as Brain, CS SSF #5.


0Chromosome 1p deletion/LOH not identified/not present
1Chromosome 1p deletion/LOH identified/present
6Benign or borderline tumor
7Test ordered, results not in chart
8Not applicable: Information not collected for this case (If this item is required by your standard setter, use of code 8 will result in an edit error.)
9Not documented in patient record Cannot be determined by the pathologist Chromosome 1p deletion/LOH not assessed or unknown if assessed

Each Site-Specific Data Item (SSDI) applies only to selected primary sites, histologies, and years of diagnosis. Depending on applicability and standard-setter requirements, SSDIs may be left blank.