De novo insG619 mutation in PAX2 gene in a Japanese patient with papillorenal syndrome

Purpose To describe a Japanese patient with papillorenal syndrome (PRS) and to identify the genetic defect responsible for the disease. Design Interventional case report. Methods Complete ophthalmologic and systemic examinations were performed, and direct genomic sequencing of the PAX2 gene. Results Fundus examination of a 3-year-old Japanese girl showed atypical coloboma bilaterally. At 6 years of age, she presented with proteinuria, and renal ultrasonography showed hypoplastic kidneys bilaterally. Molecular genetic analysis of the PAX2 gene revealed a de novo heterozygous insertion of a G at position 619. Conclusions Our findings suggest that an abnormal development of the optic stalk led to the optic disk dysplasia in PAX2-associated PRS. This indicates that we should consider renal abnormalities when an atypical round coloboma is present. Molecular genetic analysis of the PAX2 gene in combination with renal ultrasonography can help in making an earlier diagnosis of the disease.