Just now when I Googled "transgender transabled" the first few entries that turned up were (unsurprisingly) from right-wing web sites: Breitbart, Americafreedomblog, the Federalist, etc. Funny that. Sounds to me like an ideology in search of an analogy. While, unlike you, I would never be so bold as to question a person's understanding of his or her own identity, upon further reading I found that the incidence of trans-abled people is actually quite small, unlike the 2-5% of the population who identify as transgender, and that transability was recently added to the emerging measures and models appendix section of the Diagnostic and Statistical Manual of Mental Disorders. It seems that this disorder (and it is classified as a disorder) is starting to be thought of as a neurological problem with the body’s mapping, rather than a mental illness. Suffice it to say that in both the case of transgendered people and transabled people, unlike you, I believe they are to be taken at their word.