Typical renal-coloboma syndrome phenotype in a patient with a submicroscopic deletion of the PAX2 gene.

We present a patient with optic nerve hypoplasia, secondary strabismus, mild deafness, abnormal external ear helices, and renal hypoplasia. The clinical phenotype was consistent with renal-coloboma syndrome, but no point mutation in the PAX2 gene could be identified. High-resolution array comparative genomic hybridization (aCGH) analysis showed that this patient has a submicroscopic deletion on chromosome 10, affecting the entire coding region of the PAX2 gene. This finding provided the molecular confirmation of the patient's clinical diagnosis and showed that, in addition to point mutations, deletions of the PAX2 gene contribute to the etiology of the renal-coloboma syndrome.