* * ↨ ↨ * * ↨ ↨ Figure 1: Early awareness of risk for retinoblastoma optimizes therapy and outcomes. This child was examined because his sibling (triplets) presented with retinoblastoma. His right eye appeared normal, but optical coherence tomography (OCT) revealed two invisible tumors (* and ↓) (left images), which were treated with laser therapy only (right images); OCT post laser shows coagulation of tumor, visible in the retinal image.

A D I I II II B I III II IV C I V II III § * Bilateral retinoblastoma 1 2 H1 A I II III IV V 1 2 3 4 5 * § H1 H0 HX D B I II 1 2 H0* H0 H1 3 4 I 3 4 5 1 H1 H0 II III 2 C HX Figure 2: Pedigrees illustrating inheritance patterns for RB1 mutations. A. Full penetrance and expressivity for Null mutation: father (bilaterally enucleated) and 2/2 bilaterally affected offspring (I1 unilateral enucleation vision 1.0 remaining eye; all H1 with 11 base pair deletion in exon 12; diseased eye ratio (der) = 2. B. No family history, new Null mutation: triplets [insert ref to dimaras NRDP] diagnosed with bilateral retinoblastoma at age 2.5 months due to c.1345G>T (p.Gly449X) RB1 mutation resulting in no pRB; parents showed no evidence of the mutation but were considered H0* because there remains a <1% risk of mosaicism in either parent; older sib is negative for the mutation, therefore H0; der = 2. C. 100% penetrance and variable expressivity: grandfather (I1) was diagnosed with bilateral retinoma when his daughter (II1) was diagnosed with bilateral retinoblastoma, due to c.1960G>T (p.Val654Leu) missense RB1 mutation; the proband, II1, later developed meningioma in the radiation field, and breast cancer; the proband’s brother (II3) and daughter (III2) inherited the mutation and developed unilateral retinoblastoma; der = 1.5. D. Parent of origin low penetrance:[insert ref Klutz 2002] c.607+1G>T RB1 splice mutation that shows higher penetrance when inherited from father (ie II1, III1, III3; der = 1, than from mother (ie III1, III3; der = 0), likely due to increased expression from the maternal than the paternal mutant RB1 allele;[insert ref Eloy 2016] (overall der = 0.7); IV-1 had a small unilateral tumor but died at 11 years of age due to radiation induced secondary malignancies; IV-5§ has not been tested, but developed thyroid cancer. H1 = carries RB1 mutant allele; H0 = does NOT carry the familial RB1 mutant allele; H0* = <1% risk to carry familial RB1 mutant allele; HX = unknown risk to carry familial RB1 mutant allele. Bilateral retinoblastoma Unilateral retinoblastoma Bilateral retinoma

Figure 3: Retinoma, the benign precursor of retinoblastoma (stable translucent retinal mass with calcification and associate retinal pigment epithelial distrubance) was diagnosed in family C (figure 2) only when his daughter (II1) was diagnosed with retinoblastoma. He never received treatment and was alive and well at age 90 at last follow-up.

A B C/D C/D/E E Definition of Primary Tumor (cT) cTX Unknown evidence of intraocular tumor  cT0 No evidence of intraocular tumor cT1 Intraretinal tumor(s) with sub-retinal fluid ≤ 5 mm from the base of any tumor cT1a Tumors ≤ 3 mm and further than 1.5 mm from the disc and fovea cT1b Tumors > 3 mm or closer than 1.5 mm to the disc and fovea cT2 Intraocular tumor(s) with retinal detachment, vitreous seeding or sub-retinal seeding cT2a Sub-retinal fluid >5 mm from the base of any tumor cT2b Tumors with vitreous seeding and/or sub-retinal seeding cT3 Advanced intraocular tumor(s) cT3a Phthisis or pre-phthisis bulbi cT3b Tumor invasion of the pars plana, ciliary body, lens, zonules, iris or anterior chamber cT3c Raised intraocular pressure with neovascularization and/or buphthalmos cT3d Hyphema and/or massive vitreous hemorrhage cT3e Aseptic orbital cellulitis A B C/D C/D/E E Figure 4: 8th edition TNMH Cancer Staging for intraocular retinoblastoma.54 A. Clinical Staging for eyes with retinoblastoma, compared to IIRC38. B. Heritablity stage for persons at risk to carry an RB1 germline mutation.

Definition of Heritable Trait (H) HX Unknown or insufficient evidence of a constitutional RB1 gene mutation H0 Normal RB1 alleles in blood tested with demonstrated high sensitivity assays [H0* Normal RB1 in blood with <1% residual risk mosaicsm] H1 Bilateral retinoblastoma; trilateral retinoblastoma (retinoblastoma with intracranial CNS midline embryonic tumor); family history of retinoblastoma; or molecular definition of RB1 gene mutation in blood. Figure 4: 8th edition TNMH Cancer Staging for intraocular retinoblastoma.54 A. Clinical Staging for eyes with retinoblastoma, compared to IIRC38. B. Heritablity stage for persons at risk to carry an RB1 germline mutation.

Figure 5: Post-natal diagnosis of familial retinoblastoma to late to save good vision. Bilateral inherited retinoblastoma in neonate with positive family history born full term (39 weeks) and examined a 5 days after birth: right eye stage cT2b (IIRC group C), left eye stage cT1b (IIRC group B) involving both foveas; treatment with multiple periocular and systemic chemotherapies and 3 years of focal therapies salvaged both eyes with legal blindness.