Okamoto Syndrome Watchlist (log in to enable) Retrieved 2021-01-23 Source Orphanet Trials — Genes HNRNPK Drugs — Interested in hearing about new therapies? Registered! Okamoto syndrome is characterised by congenital hydronephrosis, intellectual deficit, growth retardation, cleft palate, generalised hypotonia and a characteristic face. Cardiac anomalies have also been reported. To date, 6 cases have been reported.