Novel case of dup(3q) syndrome due to a de novo interstitial duplication 3q24-q26.31 with minimal overlap to the dup(3q) critical region.

Dup(3q) syndrome is characterized by typical facial features, mental and growth retardation, often with congenital heart defects. The syndrome has attracted special attention because of the clinical overlap with Cornelia de Lange syndrome (CDLS). Patients with dup(3q) syndrome are trisomic for segments of the long arm of chromosome 3, most often within the region 3q21 to 3qter.