Heads up, none of this is my work this is a section from a research document from Vaush and others. Disagree with him all you want this thing is very handy.

Section from doc:

LGBTQ Issues Transgender People are Valid

• Forward - an incomplete list of the reputable scientific & social organizations which affirm the validity of transgender people (that transness is not an illness, that trans people are deseving of respect and equal rights, etc). This also serves as a list of the institutions which recognize the difference between sex and gender.
• American Psychological Association
• American Medical Association
• American Psychoanalytic Association
• Human Rights Campaign
• American Academy of Pediatrics
• American College of Osteopathic Pediatricians
• United Nations
• United Kingdom’s National Health Service
• https://www.apa.org/topics/lgbt/transgender
• American Psychological Association pamphlet on transgender issues
• Affirms psychological consensus - that transgender people are valid, have existed throughout history, are subject to discrimination, and that transness is not a mental disorder.
• https://www.apa.org/about/policy/resolution-gender-identity.pdf
• A 2008 Gender Identity Resolution by the American Psychological Association which expands upon the premises listed in the annotation above and supports total equality for transgender people - affirmation of the institutional legitimacy of transness in psychology.
• https://www.apa.org/about/policy/orientation-diversity
• Identical to the above, essentially, except pertaining to trans and gender-nonconforming youth.
• https://www.apa.org/about/policy/booklet.pdf
• Booklet on LGBTQ issues from the American Psychological Association, outlining their policy and attitudes towards aforementioned communities.
• Expressly positive.
• https://assets2.hrc.org/files/documents/SupportingCaringforTransChildren.pdf
• Human Rights Campaign document published with the American Academy of Pediatrics & the American College of Osteopathic Pediatricians which affirms the validity of transgender youth, encourages appropriate care and respect for their transness and provides resouces on how to do so.
• https://www.nhs.uk/conditions/gender-dysphoria/
• The UK’s National Health Service report on gender dysphoria, which affirms the validity of trans people and discusses ways in which gender dysphoria can be alleviated, the best of which is said to often be social and physical transition.
• http://www.apsa.org/content/2012-position-statement-attempts-change-sexual-orientation-gender-identity-or-gender
• The American Psychoanalytic Association’s statement on gender identity, in which transness is validated, social stigma against transgender people is cited as a serious cause of harm and ‘reparative therapy’ - attempts to suppress one’s transness and force them to live as the gender they were assigned at birth - is medically invalid.
• https://time.com/5596845/world-health-organization-transgender-identity/
• The World Health Organization recently stopped classifying transness as a mental disorder.
• https://www.babcp.com/files/About/Press/Memorandum-of-Understanding-on-Conversion-Therapy-in-the-UK.pdf
• Multilateral condemnation of ‘conversion therapy’ from essentially every medical institution in the United Kingdom, with reasons provided.
• https://www.unfe.org/about/
• Transphobia? The United Nations says no.