Background: The use of array CGH analyses for investigation of mentally retarded children has led to the identification of a growing number of new microdeletion and microduplication syndromes, some of which have become clinically well characterised, and some that await further delineation. We describe three children with de novo 17p13.1 duplications encompassing the PAFAH1B1 gene, showing similar phenotypic features, including mild to moderate developmental delay, hypotonia, and facial dysmorphism, and compare them to the few previously reported cases with this duplication.
Methods: MLPA or array-CGH was used in a clinical setting to diagnose three developmentally delayed children with duplications of 17p13. The duplications were characterised further using Agilent array technology, revealing duplication sizes from 1.8 to 4.0 Mb, with a region of overlap corresponding to 1.8 Mb.
Detailed clinical information was obtained from patient files and personal examinations.
Conclusions: We present three patients with developmental delay and similar clinical features, most likely due to a common microduplication of 17p13. In contrast to patients with deletion of the region (Miller-Dieker syndrome) our patients showed mild to moderate retardation and displayed no lissencephaly or gross brain malformations.
Further cases with similar duplications are expected to appear and will contribute to the delineation of a potential new microduplication syndrome of 17p13.