17p13.3 Microduplication Syndrome

17p13.3 microduplication syndrome is characterized by variable psychomotor delay and dysmorphic features.

Epidemiology

It has been recently described in less than ten patients.

Clinical description

Clinical presentation is variable but it is possible to delineate a common clinical spectrum comprising mild to moderate psychomotor delay, hypotonia and discrete craniofacial dysmorphic features including a high forehead with frontal bossing, a small nose and a small mouth.

Etiology

The microduplication was identified by microarray-based comparative genomic hybridization (a-CGH). It encompasses the same region that is deleted in Miller-Dieker (17p13 deletion) syndrome (see this term).. The variable size of this de novo duplication indicates that mechanisms other than nonallelic homologous recombination (NAHR) may be responsible. Additional patients will further substantiate the significance of 17p13.3 duplication and contribute to delineation of the clinical spectrum.