Mild mental retardation in a child with a de novo interstitial deletion of 15q21.2q22.1: a comparison with previously described cases.

We report on a child with mild mental retardation, hypotelorism, blepharophimosis, face slight asymmetry and partial hypoplasia of corpus callosum, with an interstitial deletion of a chromosome 15. The deletion was molecularly characterized by array-CGH and FISH techniques. This rearrangement has a 7.18Mb extension and maps to 15q21.2q22.1. To date, there have been only six individuals reported with a deletion of 15q21; in three cases, the rearrangement was characterized by molecular cytogenetic techniques. After a comparison with these three cases, it appeared that the deletion we found is one of the smallest and it overlaps the distal portion of the ones taken into account. Finally, we tried to delineate the genotype-phenotype correlation in patients with a deletion of 15q21.