Dysmorphic phenotype and neurological impairment in 22 retinoblastoma patients with constitutional cytogenetic 13q deletion

We describe the facial dysmorphic phenotype and the neurological developmen t of a series of 22 retinoblastoma patients sharing a cytogenetically detec table 13q deletion in a retrospective and longitudinal study. In most of th e cases, high-resolution banding analysis, morphological analysis, and asse ssment for neurodevelopmental outcome, as well for organ malformations, wer e performed. Chromosomal rearrangement involving the RBI gene included 20 13q interstiti al deletions (including 16 de novo deletions) and two de nolo translocation s. The most prominent dysmorphic abnormalities were anteverted ear lobes (9 0%), a high and broad forehead (85%), and a prominent philtrum (65%). This phenotype was associated with severe mental retardation and/or motor impair ment at age 2 years in 69% of patients and correlated with the size and the location of the 13q deletion. The survival rate of our series (91%) was no t different from that usually seen in retinoblastoma patients.