Today marks four months since anyone has seen Leah Rose Altmann, and her mother can’t help but fear what has happened to the 27-year-old who grew up in Royal Palm Beach and graduated from G-Star School of the Arts.

"I have two children and each have half my heart," Lynda Santamaria said Wednesday amid tears from her Royal Palm Beach home. "I literally feel like I’ve been functioning with half a heart."

Altmann last was seen leaving her Los Angeles apartment Aug. 28, three days after her birthday, carrying only a small backpack, according to a missing-persons flyer being circulated on social media. She has been living in Southern California for about two years, doing audio-visual work for TV shows — one gig was for the Food Network’s Guy Fieri — and playing bass and keyboards in a metal band called Seven Factor.

"Our keyboardists is missing. This is serious. URGENT!!!!" the band posted Nov. 17 on Instagram.

Santamaria said she fears that someone could be holding her daughter against her will — or worse — as there has been no activity on her bank accounts since September, according to information she has learned from investigators. The Los Angeles Police Department confirmed to The Post this week that it is conducting a missing-persons investigation for Altmann but provided no other details.

The Palm Beach County Sheriff’s Office took to social media Tuesday to ask for the public’s help, noting that Altmann may have been a victim of human trafficking. Santamaria said she’s been by told by people familiar with Los Angeles that the crime has become a growing concern in the area south of downtown Los Angeles where Altmann lives.

"(There has been) no banking for three months, no texts, phone calls or Facebook. Of course a mom fears that," Santamaria said.

Human trafficking: What is it, and what is being done about it

The missing-persons flyer describes Altmann as 4 feet 9 inches and 95 pounds, with blonde hair and blue eyes. The Florida International University graduate likes to travel but has never gone this long without contacting anyone, the flyer said. Santamaria said it would be unusual for Leah to leave behind things such as her makeup.

"Leah is the type, since she travels a lot, she might leave stuff behind, but not her personal-hygiene items," she said.

Altmann previously has worked in Orlando and has family in Virginia, but there has no been no indication that she has left California, her mother said. She said Altmann has dealt with some personal issues and was estranged from her family for awhile, but that their relationship had grown closer over the past two years.

G-Star founder Greg Hauptner remembered Altmann as being a bright and studious student who was a member of the Palm Springs school’s second graduating class. Altmann often was involved in the technical aspects of the school’s film and music productions, he said.

"Whatever she got into, she took seriously and worked hard at it," Hauptner said.

Anyone with information about Altmann’s whereabouts is asked to call either the Los Angeles Police Department at (323) 846-6547, or the Palm Beach County Sheriff’s Office at (561) 688-3400.