Chromosome 3 status

Disomy: 2 copies of chromosome 3 with retention of heterozygosity (ROH)

Mosaic: Heterogeneity of the tumor sample where multiple cell types are present. For example, some parts of the tumor are disomy (have the normal 2 copies of a chromosome) and some parts are monosomy (have only 1 copy of a chromosome). Tumors are created by an accumulation of genetic changes and it is common for tumors to contain heterogeneity (a mix of cell types) as the tumor evolves.

Monosomy: 1 copy of a chromosome 3 with loss of heterozygosity (LOH)

Partial Monosomy: Over 50% of the chromosome 3 has missing genetic material; the other part of the chromosome 3 maintains 2 copies.

Disomy: 2 copies of chromosome 1p with retention of heterozygosity (ROH)

Loss: Less than 2 copies of chromosome 1p

Chromosome 6p status

Disomy: 2 copies of chromosome 6p with retention of heterozygosity (ROH)

Gain: More than 2 copies of chromosome 6p

Loss: Less than 2 copies of chromosome 6p

Disomy: 2 copies of chromosome 6q with retention of heterozygosity (ROH) Gain: More than 2 copies of chromosome 6q

Loss: Less than 2 copies of chromosome 6q

Disomy: 2 copies of chromosome 8p with retention of heterozygosity (ROH) Gain: More than 2 copies of chromosome 8p

Loss: Less than 2 copies of chromosome 8p

Disomy: 2 copies of chromosome 8q with retention of heterozygosity (ROH) Gain: More than 2 copies of chromosome 8q

The data used to build PRiMeUM does not distinguish between a tumor that initiates in one region of the eye and grows into another. For example, a tumor that initiates in the ciliary body and grows into the choroid or vice versa, should be entered as “choroid, ciliary body”. Similarly, tumors involving the iris should be entered as “iris, ciliary body” or “iris, ciliary body, choroid”.