To functionally validate the two mutations, we co-injected into zebrafish embryos tmem67 MO and RNAs encoding p.Gly132Ala and p.Tyr920ThrfsX40, and observed no rescue of the hydrocephalus phenotype and the decrease in axin2. These findings indicate that the two mutations may cause COACH syndrome via altered Wnt signaling, at least in part. The gene discussed is TMEM67; the disease is Hydrocephalus.