Duplication of the Wolf-Hirschhorn syndrome critical region causes neurodevelopmental delay.

[wolf-hirschhorn syndrome]

Wolf -Hirschhorn Syndrome (WHS ) is caused by deletions on chromosome 4 p and is clinically well defined . Genotype-phenotype correlations of patients with WHS point to a critical locus to be responsible for the main characteristics of this disorder . Submicroscopic duplications of this region , however , are not known . Here we report a patient with an interstitial 560 kb duplication overlapping this critical locus . The present case shows that not only deletions but also duplications of the Wolf -Hirshhorn critical region cause mental retardation and multiple congenital anomalies . Interestingly , the duplication phenotype overlaps partially with the deletion phenotype . However , his facial phenotype differs from the typical WHS gestalt .