A Wisconsin mother has been sentenced to 17 years for causing the death of her 13-year-old disabled daughter who was found dead inside her bedroom without food and wearing a filthy diaper.

Nicole Gussert, 39, of Appleton, was convicted of neglecting a child and causing the death of her daughter Brianna Gussert, as well as possession with intent to deliver amphetamine.

Authorities discovered young Brianna dead inside her filthy bedroom in May 2017 and an investigation revealed she died of sepsis after being left alone for several days.

Outagamie County Judge Gregory Gill ordered Nicole to serve nearly two decades in prison and 12 years of probation. She received an additional four years for selling her prescription Adderall to friends.

Nicole Gussert (left) was sentenced to 17 years in prison and 12 years of probation after being convicted in her daughter's death

Brianna Gussert (pictured), who had Wolf-Hirschhorn syndrome, died at age 13 after she was left inside her bedroom with no help

During court, Nicole admitted that her care for Brianna before her death was ‘unacceptable.’

She told the judge her actions weren’t out of ‘malice or spite,’ that she loved Brianna very much and that she ‘failed her.’

Wolf-Hirschhorn syndrome, a rare birth condition, left Brianna unable to speak or walk, court records said.

Nicole told authorities that she couldn’t remember when or how many times she fed her daughter the previous day.

Greg Gussert, Brianna’s father, also spoke out during court and described being depressed since his daughter’s passing.

He told Post Crescent: ‘I miss Brianna every day. My heart is forever broken.’

Nicole previously pleaded no contest in February 2019.

Authorities said Nicole Gussert's (pictured) home had a stench, flies and rotting fruit

The horrific incident was uncovered when authorities were called to the Gussert’s home to perform a wellness check.

A responding officer described ‘a smell in the air of rotten food, human waste and death’ in the home, Post Crescent reported.

They said rotting food, flies and cluttered garbage could be seen throughout the home.

‘…Various bugs and partially consumed or decayed food as well as a distinct odor of feces and urine coming strongly from the deceased juvenile's room area,’ ABC 2 reports.

When Brianna was found, she was unfed, wearing an unchanged diaper and part of her skin had started to decompose.

It’s believed Nicole left Brianna unattended inside the bedroom for more than five days.

Greg Gussert (pictured), the father of Brianna Gussert, has an emotional reaction after giving a victim impact statement during sentencing in Nicole Gussert's trial at the Outagamie County Justice Center in Appleton, Wisconsin

Brianna is pictured with her father Greg (left) months before she would die in her mother's home in 2017

Brianna weighed just 32 pounds at death after losing 12 pounds in one month.

Nicole told officers that she couldn’t remember when or how many times she fed her daughter the previous day.

She also admitted to feeding Brianna protein shakes from a convenience store instead of formula shipped from a medical supply company because the protein drinks contained muscle builders.

Nicole Gussert sits with her attorney during sentencing in her trial at the Outagamie County Justice Center on Thursday

While caring for her daughter, Nicole denied assistance from Aging and Disability Resource Center, economic support and transportation for her daughter.

Nicole told law enforcement that he had been battling depression and not taking her prescription Adderall, but officers found texts that showed she was selling pills or giving them to people she owed money.

Outagamie County District Attorney Melinda Tempelis suggested that Nicole treated her dog better than she did her daughter.

‘She is able to care for another living creature, but doesn't have the decency that weekend, at all, to walk upstairs and check on her daughter,’ Tempelis said.