JULIA Roberts choked back tears as she described the death of a 10-year-old girl with Rett syndrome.

The Hollywood star, who won as Oscar last year for her role in Erin Brockovich, appealed directly to politicians in Washington for more money to research the neurological disorder that mainly afflicts young girls.

"This is very impressive and nerve-racking," Roberts said as she took her seat in a crowded room for a hearing of the US house appropriations subcommittee responsible for public health spending.

"These are the voices that we hear today in the halls of Congress," Roberts said of over-enthusiastic outbursts from children sitting behind her.

"They listen but cannot speak. They struggle to do the many things we take for granted everyday."

Roberts told lawmakers she decided to help raise public awareness for the condition after meeting Abigail Brodsky of Brooklyn, New York.

Abigail, who filmed a one-hour documentary with the actress for the Discovery Health Channel, died in June, aged 10.

"Abigail was my pal," Roberts said, close to tears. "We spent time together without words. We connected with our eyes."

Roberts asked for the subcommittee to set aside $15.5m in its 2003 budget, which starts in October.

This year, research on Rett Syndrome received $3.5m in federal funds.