The use of hormone treatments for young people who want to undergo gender reassignment is to be examined by experts, it has emerged.

The announcement by NHS England comes just weeks after the start of a landmark legal challenge to the prescribing of drugs to delay puberty. The case has been brought against the Tavistock and Portman NHS foundation trust, which runs the UK’s only gender-identity development service (GIDS).

The current clinical policies related to the use of hormone treatments will now be examined by a group headed by Dr Hilary Cass, a former president of the Royal College of Paediatrics and Child Health. The NHS said it was part of a planned review of gender identity development services for children and young people in 2020. It will publish findings later this year.

The National Institute for Health and Care Excellence (Nice), which oversees the guidance on clinical practice, is also reviewing the latest clinical evidence to help inform the work of Cass’s group.

The number of young people referred to the GIDS has increased from 678 in 2014-15 to 2,590 in the past year. Cass will lead a team of 20 experts on the review. She said: “This is a fast-developing area of medicine with emerging evidence and high public interest. I look forward to chairing this independent group, bringing together medical and non-medical experts with a range of perspectives, to make evidence-based recommendations about the future use of these drugs.”

A spokeswoman for the Tavistock and Portman trust said: “GIDS adopts an evidence-based approach to the care of children and young people with gender identity development issues and works on a case-by-case basis. We welcome this independent review of the current evidence. We know we provide a good service to our patients and their feedback is overwhelmingly positive.

“As ever, we welcome the opportunity to think with others as to how to continually improve on the care we provide. We have always contended this is a rapidly changing area of clinical practice that warrants regular and informed review.”

The review comes soon after a legal challenge to the trust by Keira Bell, 23, who was given hormone blockers and cross-sex hormones as a teenager. Her case contests the way in which consent is obtained by the clinic for the treatment of children. Bell has since detransitioned.

Her legal team told the high court last month that the clinic’s approach was unlawful because the potential risks of treatment were not adequately explained and that children could not give informed consent for this kind of treatment. The case could have serious implications for the issue.

The trust has said it was not appropriate to comment on the legal proceedings at this stage, but that GIDS “is one of the longest-established services of its type in the world with an international reputation for being cautious and considered”.