A baby at the centre of a landmark case over whether life support can be withdrawn has an "intolerable life", the High Court has heard.
Baby MB is not mentally impaired
Baby MB, who cannot be named, has spinal muscular atrophy - a genetic condition which leads to almost total paralysis - and cannot breathe unaided.
Doctors treating the 17-month-old say it is in his best interests to withdraw ventilation and to let him die.
But his family says he has a reasonable quality of life and should stay alive.
They feel he can recognise and respond to them, and that he gains enjoyment from spending time with his family.
An injunction reporting any details of the case has been lifted after an application by the BBC, but none of the parties involved can be identified.
A medic known only as Dr S told the court one had to consider the baby's inability to express his wishes, move or show if he is in any pain or distress.
When questioned by Caroline Harry Thomas, counsel for the Children and Family Court Advisory Support Service, representing the child's interests, he said: "I think the cumulative effect of all this is that he has an intolerable life."
The doctor said the child would have to live through a period in which he was unable to open his eyes, if the current treatment regime continued.
He would need them opened manually to be able to see, he added.
Baby MB has also been wearing splints on his hands and feet intermittently, which caused discomfort, and a risk of limb fractures would develop in relation to normal handling.
Charles Foster, counsel for the family, asked Dr S whether he thought the hospital's application to remove ventilation was premature.
Dr S said he disagreed, replying: "I would actually say that it could be seen as an application that is later than it should have been."
The child's neurologist, also known only as Dr S, was asked by the judge whether he would regard it as acceptable medically and ethically to continue ventilation but not to resuscitate should the child go into collapse.
He said continuing the specific treatment would not be in the child's best interests.
"If you ask me personally whether I could continue it, I would say I would find it difficult, because I have been feeling that what I have been doing as a doctor has been wrong for many months, which is a very difficult position for me to be in.
"That is not just my opinion, but the opinion of many medical professionals who are directly involved in his care," he added.
He also said he would find it very difficult to attempt resuscitation if he was asked to on the child but that it was "a very difficult dilemma".
Dr S also claimed baby MB did not have the cognitive features normally seen in children with this type of spinal muscular atrophy.
He said in his view, MB's cognitive function "does not appear normal", but it was impossible to assess because of the baby's inability to respond.
Dr S also said he was not aware of a similar child being ventilated in the UK.
The judge then asked if there was a danger that one might terminate his life when he was content and getting pleasure out of life.
Dr S responded that although he had no way of assessing it, he said he couldn't say absolutely that he did not have periods of pleasure.
"I still would say that in my assessment, the potential disbenefits outweigh the potential benefits. Our interventions I wouldn't regard as pleasurable."
Last week, Mr Justice Holman who is hearing the case, said it could be a landmark one as it was the first time a court had been asked to make a life or death ruling on a child who has near or full cognitive function.
His incurable condition, which affects one in 6,400 newborns, is set to lead to almost full paralysis.
It is a recessive genetic condition passed to a baby when both its parents carry a certain gene.
The case will continue until Tuesday.