Trisomy 13 and Rubinstein-Taybi syndrome.

Initial diagnosis of Rubinstein-Taybi syndrome was made in an infant with a prominent nose and broad thumbs and first toes. However, due to the presence of other anomalies such as low-set, malformed ears, anti-mongoloid slant of the eyes, colobomata of the iris, and cleft palate, cytogenetic studies were carried out and the diagnosis of trisomy 13 was confirmed. Since, occasionally, trisomy 13 syndrome may mimic the Rubinstein-Taybi syndrome, cytogenetic studies should be considered in all patients with clinical diagnosis of Rubinstein-Taybi syndrome.