Oceanic crust is constantly formed at mid-ocean ridges, where tectonic plates are tearing apart from each other. As magma that wells up from these rifts in Earth's surface cools, it becomes young oceanic crust. ... Just as oceanic crust is formed at mid-ocean ridges, it is destroyed in subduction zones.
Topiramate
Topiramate is the drug which might be responsible for this malformation.
Topiramate is an anticonvulsant drug which is taken alone or with other drugs to prevent and control epilepsy. Topiramate is produced in four forms and are all taken by mouth. Topiramate has many side effects which include birth defects if is taken during pregnancy, osteoporosis, vision loss, nervousness and upper respiratory tract infection.