One study published in the International Journal of Transgender Health found that in 20% of identical twin pairs, if one twin was trans, the other was as well, compared to only 2.6% of non-identical twins where this was the case; researchers attribute this to their shared genetics.Sexologist Ray Blanchard created a taxonomy of male-to-female transsexualism that proposes two distinct etiologies for androphilic and gynephilic individuals; this taxonomy has become controversial, supported by J. Michael Bailey, Anne Lawrence, James Cantor and others, but opposed by Charles Allen Moser, Julia Serano, and the World Professional Association for Transgender Health. Focus on trans women over trans men
Historically, formal efforts by the medical community to provide transsexual healthcare were extremely focused on transsexual women, with little thought for transsexual men. Julia Serano suggests that effemimania (the idea that male femininity is more psychopathological than female masculinity) was the driving factor. She sees this as a kind of transmisogyny (hatred of trans women as an extension of sexism). : 126–127  This effimimania conflates male homosexuality, MTF transsexuality, and feminine gender expression, while treating them all as a disease. : 129  She points to the medical communitys long love of now outdated theories such as autogynephilia. : 131

Medical assistance
Individuals make different choices regarding sex reassignment therapy, which may include hormones, minor to extensive surgery, social changes, and psychological interventions. The extent of medical intervention is a highly personal decision: there is no one-size-fits-all solution. Hormone replacement therapy
Transsexual individuals frequently opt for masculinizing or feminizing hormone replacement therapy (HRT) to modify secondary sex characteristics.
Bladder pressure can be measured by cystometry, during which the bladder is artificially filled with a catheter and bladder pressures and detrusor activity are monitored. Patterns of involuntary detrusor activity as well as bladder flexibility, or compliance, can be evaluated. The most valuable test to test for detrusor sphincter dyssynergia (DESD) is to perform cystometry simultaneously with external sphincter electromyography (EMG). Uroflowmetry is a less-invasive study that can measure urine flow rate and use it to estimate detrusor strength and sphincter resistance. Urethral pressure monitoring is another less-invasive approach to assessing detrusor sphincter dyssynergia. These studies can be repeated at regular intervals, especially if symptoms worsen or to measure response to therapies.Evaluation of kidney function through blood tests such as serum creatinine should be obtained.Imaging of the pelvis with CT scan or magnetic resonance imaging may be necessary, especially if there is concern for an obstruction such as a tumor. The inside of the bladder can be visualized by cystoscopy. Treatment
Treatment depends on the type of neurogenic bladder and other medical problems. Treatment strategies include catheterization, medications, surgeries or other procedures. The goals of treatment is to keep bladder pressures in a safe range and eliminate residual urine in the bladder after urination (post-void residual volumes). Catherization
Emptying the bladder with the use of a catheter is the most common strategy for managing urinary retention from neurogenic bladder. For most patients, this can be accomplished with intermittent catherization which involves no surgery or permanently attached appliances.