Association of syndromic mental retardation and autism with 22q11.2 duplication.

We describe a 5.3-year-old girl with autism, mental retardation, hypotonia, marked speech delay, and mild dysmorphic features with a 22q11.2 duplication. Her mother carries the same duplication and presents cleft palate, and normal intelligence. The clinical and behavioural phenotype of this relatively new syndrome is very heterogeneous, with high variability also in the familiar cases. Up till now, about 50 cases of 22q11.2 duplication have been reported, but only three of them are associated with autistic disorders. We propose that in addition to 22q13.3 deletion syndrome, also 22q11.2 duplication should be suspected in a patient with unspecified dysmorphisms, mental retardation, autism, hypotonia, and severe speech delay.