Abstract
We report on a 7-year-old Japanese boy who presented with bilateral cryptorchism and renal insufficiency. Although the patient had fair visual acuity, he was found to have bilateral optic nerve coloboma with partial retinal detatchment. We identified a Guanine 619 insertion in exon 2 of PAX2 gene in this patient. Human PAX2 mutation syndrome or Renal-coloboma syndrome (RCS), resulting from autosomal dominant mutations in the PAX2 gene, has recently been characterized. In addition to renal hypoplasia and optic nerve coloboma, the clinical features of patients with this syndrome are vesico-ureteral reflux (VUR), high frequency hearing loss, and central nervous system (CNS) anomalies. Our patient had bilateral small kidneys with renal insufficiency which currently progressed to end stage renal failure at the age of 15. The pathological diagnosis of kidney biopsy in our patient at the age of eight was mild mesangial proliferative glomerulonephritis. This pathological findings have been well described with RCS and may be one of the characteristic features of the syndrome. On the other hand, the patient had bilateral cryptorchism which has not been described in RCS.
