Microdeletion in distal 17p13.1: A recognizable phenotype with microcephaly, distinctive facial features, and intellectual disability

Abstract

Array comparative genomic hybridization has led to the identification of new syndromes by identifying genomic imbalances not detectable by standard karyotyping methods and by allowing correlations with physical findings. Deletions in the 17p13.1 region have been reported in patients with dysmorphic features and developmental delay but a consistent phenotype has yet to emerge. This report describes two unrelated patients with a characteristic phenotype associated with overlapping de novo deletions in the distal region of 17p13.1 detected with array comparative genomic hybridization and confirmed by real-time PCR. These patients share remarkably similar clinical features including microcephaly, mild developmental delay, generalized joint laxity, and a body posture with knee and elbow flexion and hands held in midline. They have distinctive facial features which include long midface with retrognathia with overbite, and protruding ears. The deletions in both patients are the smallest ever reported in this region (approximately 252 and 219 kb). The overlapping region contains 18 genes. Various isolated deletions of the 17p13.1 region have been reported previously without delineation of a consistent phenotype. We propose that the described microdeletions in the distal portion of 17p13.1 represent a novel microdeletion syndrome.