Double trisomy 48,XXX,+18 in a newborn

We report the 6th case of double trisomy X and 18, ie, 48,XXX,+18. The infant lacked overlapping fingers, simian creases, and structural heart disease and is alive at 275 days. Two X chromosomes were late replicating. Anomalies of the hands and kidneys involved only the right side in the present case; review of the five previous cases of 48,XXX,+18 also showed that anomalies of kidneys, hands, and ears affected predominantly the right side in three patients.