About 88% of children who have gender dysphoria do not hold those beliefs when they grow older.
https://archive.is/eWGp2
https://archive.is/jyQVD
MRI scans indicate that MtF transsexuals are either men aroused by the thought of possessing female genitalia or homosexuals who want to seduce straight men.
https://archive.is/8wMFZ
41% of transsexuals have tried and failed to commit suicide.
https://archive.is/6Evel
53% of mothers of transsexual children have Borderline Personality Disorder, compared to only 6% of mothers of normal children.
https://archive.is/xZ8Ie
Adult Gender Identity Disorder (GID) Can Remit
https://archive.is/Qro5Y
Sixty percent reported one or more types of severe child abuse.
https://archive.is/kG48B
The frequency of personality disorders was 81.4%. The most frequent personality disorder was narcissistic personality disorder (57.1%) and the least was borderline personality disorder. The average number of diagnoses was 3 per patient.
https://archive.is/RMNa1
Persons with GID compared to heterosexuals have higher presence of PDs, particularly Paranoid PD, avoidant PDs, and comorbid PDs.
https://archive.is/PHs9D
Evidence suggests over-representation of autism spectrum disorders (ASDs) and behavioral difficulties among people referred for gender issues […] As compared to non-referred comparisons, participants with ASD were 7.59x more likely to express gender variance; participants with ADHD were 6.64 times more likely to express gender variance. Autists have around 8x more GID and people with ADHD around 7x the average.
https://archive.is/gLdzi
Clinical evidence suggests that schizophrenia occurs in patients with GID at rates higher than in the general population and that patients with GID may have schizophrenia-like personality traits. Conversely, patients with schizophrenia may experience alterations in gender identity and gender role perception.
https://archive.is/mV9Ic
Of 139 boys which had GID at the first study only 12% had it 12 years later, 47% were bi/gay and 41% were hetero or asexual.
https://archive.is/Jru5t
Eighty-three patients requesting sex reassignment surgery (SRS) were recruited and assessed through the Persian Structured Clinical Interview for DSM-IV Axis I disorders (SCID-I). Results. Fifty-seven (62.7%) patients had at least one psychiatric comorbidity. Major depressive disorder (33.7%), specific phobia (20.5%), and adjustment disorder (15.7%) were the three most prevalent disorders.
https://archive.is/dycBX
There is no, zero, null evidence to suggest that it is neurological in the sense that you are trying to push. There is a mountain of evidence to suggest that it is a mundane mental illness, specifically brought about by other mental illness i.e narcissism or autism.