Figure 2. Three families with low-penetrance retinoblastoma

A: Family segregating the previously described p.R661W mutation. Mutation carriers of this family presented uni- or bilateral retinoblastoma (RB) or were unaffected. B: Family segregating a novel nonsense mutation g.2157dupC in exon 1 that was carried by both the proband, who had bilateral RB and his father who had unilateral RB. Mutations in the first exon could be associated with low-penetrance by alternative in-frame translation. C: Family segregating a novel duplication mutation in exon 1, g.2179_2183dupGGACC that was carried by the proband, who had bilateral retinoblastoma, his father who had unilateral RB and unilateral retinocytoma in separate eyes and his only sister who had unilateral RB. Bar on top of symbol represent tested individuals, asterisk represents mutation carriers, shaded symbols represent bilateral RB; half-shaded symbols represent unilateral RB, dashed symbols represents deceased individuals, and arrow represents proband.