Nineteen-year-old Esteban Navarro was assaulted on a soccer pitch by six people, who attacked him with knives, iron bars and machetes, while calling him “maricon” (faggot), on 23 June.
According to local media reports, the attack was initiated when one of assailants came to believe that his 40-year-old father was in an alleged relationship with Navarro.
The young man was taken to hospital with multiple injuries that led to the loss of his right foot.
Doctors have now begun the process of amputating his right leg in a series of operations that could take months.
The Homosexual Movement of Integration and Liberation (MOVILH) has filed attempted murder charges on behalf of Navarro against three of the teenage attackers who have been identified.
"We are very sad and concerned," said the boy's family in a statement released by MOVILH.
"We hope that there will be justice and that those responsible will be punished to the fullest extent of the law. Esteban's life has changed dramatically in this homophobic attack."
A spokesman for MOVILH, Oscar Rementería, slammed "the lack of public pronouncements by authorities in this case. Apparently, for some, solidarity and commitment to non-discrimination is determined by the media impact of a particular event, rather than by the severity of the violations."
Last year, Chile passed a hate crimes bill that will punish offenders more harshly in cases in which victims are targeted because of their sexual orientation, race, gender, religion or nationality.
The bill was given added impetus following the murder of 24-year-old Daniel Zamudio who was viciously assaulted by neo-Nazis in March 2012 for being gay.