Further characterization of microdeletion syndrome involving 2p15-p16.1.

We report on a patient presenting with cognitive delay, prenatal and postnatal growth deficiency, microcephaly, ptosis of eyelids, high and broad nasal root, and camptodactyly. Analysis of a dense whole genome single-nucleotide polymorphism (SNP) array showed a de novo 3.35 Mb deletion on 2p15-p16.1. In order to study the parental origin of the deletion we analyzed selected SNPs in the deleted area in the proband and her parents showing Mendelian incompatibilities suggesting a de novo deletion on the chromosome of paternal origin. Based on the five cases described previously in the literature, we have narrowed the critical region responsible for the 2p15-p16.1 microdeletion syndrome phenotype. The critical region does not include the VRK2 gene that had been speculated to have a role in cortical dysplasia. However, the association of the VRK2 gene with cortical dysplasia remains to be determined, as MRI imaging of the brain and gene content of the 2p15-16 deletion becomes established in more patients.