It's hard for a special ed teacher to know about all disabilities where they can manage an IEP (and the SDI needed to reach goals) for every student.  Deaf & HOH are rare.  Schools should be open to consulting to better understand rare disabilities.  Consultants will often come with a price tag & teachers are spread thin with what they need to do (if they want to do their own research) so I see this as a lack of time & money with being able to provide FAPE for these students.  Without strong parent advocacy, I see students like this slipping through the cracks.