Eastbourne MP Caroline Ansell has met with Poirot actor David Suchet to discuss funding treatment for Tuberous Sclerosis.
The TV personality has a grandson with the extremely rare condition and Caroline also has a family member who has TS.
She joined children, parents and campaigners last week to take part in the Tuberous Sclerosis Association's (TSA) lobby of Parliament.
The Prime Minister, Theresa May, has now agreed to meet the group and talk about its campaign for NHS England to approve the Everolimus drug, which treats brain tumours caused by Tuberous Sclerosis Complex (TSC).
Just 20 young people a year in the country develop these particular tumours.
“Anybody who knows me is very aware of how much this matters to me personally, and I am delighted that the Prime Minister has now agreed to meet with the TSA and others to discuss a way forward,” said Caroline.
“It was good to meet so many families who have to cope with the condition and to chat with David, who is passionately involved in the campaign.
"The issue has my full support and I look forward to hearing about progress following the meeting with the PM."