Retinoblastoma, pinealoma, and mild overgrowth in a boy with a deletion of RB1 and neighbor genes on chromosome 13q14.

We report on a 10-year-old boy with a normal karyotype and a chromosome 13q14 deletion of the retinoblastoma gene (RB1) by fluorescence in situ hybridization (FISH). He showed subtle signs of overgrowth, including macrocephaly, hepatomegaly, and inguinal hernia. The boy also had cryptorchism and mild developmental delay. In his first months of life, variant Wiedemann-Beckwith syndrome was tentatively suspected and he was included in a careful tumor prevention program. At the age of 11 months, bifocal retinoblastoma of the left eye was diagnosed. Pinealoma was suspected at the age of 19 months and was removed by neurosurgery at the age of 29 months. At 4 years and 4 months, the deletion of the RB1 gene was suspected on clinical grounds and was diagnosed by FISH and molecular studies. At that time, he was a near-normal healthy playful kindergarten child, height 107 cm (-0.3 SD), OFC 52.5 cm (+0.8 SD), developmental age 3-3.5 years. The combination of retinoblastoma, pinealoma, and deletion of the RB1 gene diagnosed by FISH has not been reported previously. The deletion spans at least 370-420 kb in size and is predicted to include proximal and distal neighbor genes. This report may assist in establishing the clinical signs of the contiguous gene syndrome at the RB1 locus on 13q14.