The guidelines to help parents and teachers track lesbian, gay, bisexual and transgender (LGBT) symptoms in their children has stereotyped the group, say experts and psychologists.
Consultant paediatrician Dr Sim Joo Seng said the sexuality of a person may not be established until late puberty.
"Giving guidelines to teachers who are untrained to do so is a dangerous move," the Star Online quoted Joo Seng as saying.
The guidelines, among others, cautioned parents about their sons wearing tight V-neck shirts and bright coloured attire, and their daughters being frequently seen in the company of certain girls while ignoring others.
Dr Sim said the guidelines stereotyped the LGBT community and could lead to bigger problems such as discrimination and intimidation.
Clinical psychologist Sylvester Lim likened the guidelines to "a ridiculous attempt" to describe the LGBT community without any supporting research.
The Congress of Teaching Services in National Education (Kongres), however, has come out in support of the guidelines as "these help teachers to solve problems of youths with LGBT tendencies."
"LGBT is not suitable for our Malaysian culture and we want to help those who have this problem," Congress president Jemale Paiman said.