Single mother Erin Kelly received a life-changing diagnosis in June.

But the 29-year-old from Eagleby, Queensland, has known since she was a teenager that one day Alzheimer’s disease, which is the most common cause of dementia, could come for her.

“My mum died of Alzheimer’s when she was 50,” Kelly told www.20304050.best.

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“The disease took my grandfather at 45, and my aunt when she was the same age.

“I just didn’t think it would come for me so soon.”

In May 2024, tests confirmed Kelly had inherited a rare genetic mutation called PSEN1 from her mother, Robyne.

Carriers of the genetic mutation are at high risk of developing Alzheimer’s disease — a progressive brain condition that causes memory loss and cognitive decline — often before the age of 65.

In June, scans revealed the first signs of damage to Kelly’s neurons, which are cells in the brain that carry messages.

When the mum-of-one was given the official diagnosis of early onset Alzheimer’s, Kelly says, “I was in a bit of denial at first”.

While dementia can happen to anybody, it is most common after the age of 65.

A diagnosis of any kind of dementia when you’re younger than 65 is called early onset dementia, or younger onset dementia, and is extremely rare.

While Kelly’s doctors can’t say how quickly the disease will progress, it will soon begin to affect her memory, thinking and behaviour, with her condition expected to deteriorate over time.

“I’ve started to notice small changes already,” Kelly said.

“Forgetting words and mixing words together.

“I’ll be thinking of something, and I’ll just mush the words together.

“It’s things I didn’t do previously.”

There is no cure, but Kelly is determined to spend the time she has left making lasting memories for her daughter, Evie, 8.

“We’re not exactly sure how or what to tell her yet. She’s still so young,” Kelly explained.

“She will get some information, but we want to protect her for as long as we can.

“The goal is to see her finish school, get married.

“I want to make sure she’s an adult before I die.”

Erin’s stepsister Jessica Simpson has set up a Go Fund Me page for Kelly to raise money for a treatment called lecanemab (LEQEMBI).

The treatment could help slow down how quickly the disease progresses.

In October 2024, the TGA made the decision not to register the medication in Australia, meaning 18 months of treatment could cost Kelly up to $90,000.

“Even with a confirmed diagnosis, Erin has been told she’s too young to qualify for clinical trials in Australia,” Simpson explained.

“This treatment could give her more time to keep working, keep functioning and most importantly, keep being Evie’s mum for as long as she can.”

According to Dementia Australia, dementia is the term used to describe the symptoms of a large group of illnesses which cause a progressive decline in a person’s functioning.

It is a broad term used to describe a loss of memory, intellect, rationality, social skills and physical functioning.

There are many types of dementia, including Alzheimer’s disease, vascular disease, frontotemporal dementia and Lewy body disease.

Today, there are roughly 433,000 Australians living with dementia and there are an estimated 29,000 people living with younger onset dementia, which can include people in their 30s, 40s and 50s.

“Most people don’t associate Alzheimer’s with someone so young,” Jessica said.

“Someone still packing school lunches, doing bedtime stories and showing up every day for their child.

“But this is Erin’s reality. And sadly, it’s progressing fast.”