An 8-year-old boy was brought to the nephrology and rheumatology department with a 3-day history of abnormal renal function and three episodes of twitching. Laboratory studies showed a creatinine level of 331.8 μmol/L, and color Doppler ultrasonography showed that the bilateral kidneys were small and unstructured (Fig. 1A and 1B). In addition, we found that the proband had an abnormal “morning glory” disc (Fig. 1C and 1D), and ultrasound showed a limited dent in each optic disc (Fig. 1E and 1F). These symptoms are similar to those found in renal coloboma syndrome. Interestingly, a 24-hour dynamic electroencephalogram revealed the occurrence of a paroxysmal epileptic wave during wakefulness (Fig. 1G). Such cases of renal coloboma syndrome with epilepsy were sporadic.

The patient had no family history (Fig. 2A) of similar diseases and had a c.70dupG (NM_003987) de novo heterozygous mutation in paired box 2 (PAX2) (Fig. 2B), which is responsible for renal coloboma syndrome. He was discharged when the tic subsided, and renal function improved slightly after 14 days of treatment with alkali therapy for acidosis and orally administered sustained-release sodium valproate tablets. A follow-up review was performed after 1 month, during which time the patient had been treated according to the doctor’s advice at home. The patient showed maintenance of renal function along with a decrease in convulsions, but there was no significant improvement in his ocular disease.