Branchial arch defects and 19p13.12 microdeletion: defining the critical region into a 0.8 M base interval.

We present a patient with preauricular tags, preauricular and branchial pits, stenosis of the external auditory canals, mild hearing loss, and mild developmental delay who had a de novo 19p13.12 submicroscopic deletion. The size of the deletion was 760-kb, extending from 15,300,338 to 16,064,271 (hg18; NCBI Build 36.1). Our finding supports the notion that 19p13.12 represents a unique microdeletion syndrome characterized by branchial arch defects and the concept of exclusion mapping indicates that the putative locus for the branchial arch development is included in the 0.8-Mb interval defined by the deletion in the presently reported patient.