The mother of baby Charlie Gard broke down in tears during a High Court hearing as a specialist gave evidence about her son's condition.
Sobs from Connie Yates could be heard in court with the judge halting the hearing on Wednesday (April 5).
She said "I'm sorry" to Justice Francis who gave the loving mother time to compose herself.
She returned to court later.
Miss Yates of Bedfont, and partner Chris Gard, want to take their son Charlie, who suffers from a rare genetic condition, to America for treatment that could help him.
Thanks to donations they have reached their £1.2m to cover the medical treatment costs.
However, specialists at Great Ormond Street Hospital (GOSH) disagree, and say Charlie should be moved to a palliative care regime.
They believe it is time to stop providing life support as he also has brain damage.
Mr Gard on Wednesday asked the judge: "Please give him a chance."
Born on August 4, 2016, the eight-month-old has a form of mitochondrial disease which causes progressive muscle weakness, the judge has been told.
Justice Francis has been asked to make decisions about what is in Charlie's best interests.
He is analysing evidence at a hearing in the Family Division of the High Court which started on Monday (April 3).
A children's intensive care specialist at GOSH had been giving evidence when Miss Yates broke down.
He said Charlie was no longer responsive, and it was hard to be sure whether the little boy was in pain.
"Charlie has deteriorated hugely since he first came to us," he said.
"The disease has affected his brain to the extent that he is completely ventilator-dependent."
He said his brain had deteriorated "so much", adding "this situation is not a tolerable one to leave a child in.
"It is really hard to see how he could possibly benefit (from treatment)."
He continued with saying that experts felt there was a small chance treatment would work and said, even if it did, Charlie's life could not be made "tolerable".
Speaking about Charlie's illness, the specialist then said: "It is not just irreversible, it is progressive."
Mr Gard listened to proceedings with his son's cuddly toy monkey tucked into the top pocket of his jacket.
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