Two Melbourne brothers in their 20s are devastated over the theft of a computer containing hundreds of photos of their mother who died earlier this year.

The laptop belonging to Mark Leatham, 21, was stolen on Monday from his southeast Melbourne home in Manuka Drive, Berwick.

Mark and his older brother were primary carers for their mother Jayne for much of their lives as she battled the rare degenerative condition called Pompe disease.

"Her sons gave her the most wonderful support, she was devoted to them and they to her, this is very, very hard for them," Jayne's emotional sister Bronwyn Morkham told reporters on Wednesday.

"She couldn't breathe independently, couldn't walk and was in a wheelchair, had very limited movement and was completely dependent for most things of daily living.

"Mark and his brother had been her primary carers for most of their lives, they've had to do most of this on their own, these photographs are really the only things they have left of Jane, they didn't have a lot."

Jane died in February at the age of 49 and her passing was "still recent and raw for us", Ms Morkham said.

Mark and his brother had only recently moved into their home after being forced out of their adapted housing department house when their mother died.

Mark said the Acer computer contained hundreds of photos of his mother.

"This is pretty hard, I am pretty upset, I don't really care about the laptop, the hard drive would be good," he told reporters.

Casey Crime Investigation Unit Detective Michael Thompson appealed for any witnesses to the burglary or anyone with information to contact Crime Stoppers on 1800 333 000 or visit www.crimestoppers.com.au.