Table 5.

Distribution of patients with criteria for hereditary Rb at diagnosis

Criteria for hereditary Rb	Number	Percent
Total of families with at least one criterion for hereditary Rba	50	36.2
Only one criterion present:
Bilateralb	39	75.0
Trilateralc	3	5.8
Family history of Rbac	3	5.8
Two criteria present:
Bilateral and family historyc	7	13.4
Samples collected for mutation analysis based on criteriad	25	48.1
RB1 mutation identifiede	13	52.0
Patients with secondary malignant neoplasmf	2	15.4

^aTwo families with two patients with Rb; ^bThree cases of unilateral Rb with family history of Rb (all diagnosed before 12 months of age); ^cTotal cases with family history of Rb = 10; ^dTotal patients who collected samples for molecular genetic testing = 32 (22.9 %); RB1 mutation was detected in one patient who had no criteria for hereditary Rb at diagnosis (unilateral and unifocal); normal results (n = 12); no results available (n = 6). This percentage (48.1 %) refers to the proportion 25/52; ^eThis percentage (52.0 %) refers to the proportion 13/25; ^fThis percentage (15.4 %) refers to the proportion 2/13