A High Court Judge has ruled that doctors can administer "plasma exchange treatment" to a seriously ill teenager after the boy's mother – a Jehovah's Witness – objected on religious grounds.

Following a hearing in the Family Division of the High Court, Mr Justice Cobb ruled in favour of specialists treating the 13 year old boy after concluding that he faced "potentially catastrophic ill health" following a rapid decline caused by a disease which affected his central nervous system.

Justice Cobb said: "In my judgment, and taking account of the risks advised, and the views of his mother, I am nonetheless clearly of the view that it is in (his) best interests that he should receive this treatment and should receive it immediately in order to give him the best possible prospects of recovery."

According to a report in the Telegraph, the mother was said to be "unhappy" with the ruling.

Based on their interpretation of biblical commandments against ingesting blood, Jehovah's Witnesses reject blood transfusions and the use of other products derived from blood.

Justice Cobb's ruling follows a similar ruling by Justice Keehan in February that a seriously ill new-born should receive surgery, including any necessary blood transfusions, at University Hospital Coventry and Warwickshire. In this case the parents – both Jehovah's Witnesses – refused to consent to the treatment on religious grounds but did not take any active steps to prevent the ruling.

Dr Antony Lempert, Chair of the Secular Medical Forum (SMF), said: "This case is another example of the serious risks faced by some children born into families where religious dogma is given greater respect than essential medical care for the children in the family. The judge was quite right to overrule the religious objection raised by this boy's mother but wrong to collude with the myth that the mother was 'unable' to give her consent. The lack of consent was a choice made by the mother; a choice for which she should be held as accountable as other parents who choose to harm their children for whatever reason. The fact that religion may sometimes be seen as an excuse for allowing harm to one's children has been recognised by the doctors' regulatory body, the GMC in its 2012 guidance. This GMC guidance states that: 'In some cases it may be difficult to identify where parents' freedom to bring up their children in line with their religious and cultural practices or beliefs becomes a cause for concern about a child's or young person's physical or emotional well-being'.

"The SMF supports parents who wish to make reasonable decisions about their child's upbringing and supports competent adults who wish to make major decisions about their own treatment. However, there should be no confusion that adults should not have the right to procure dangerous treatments for, or to withhold necessary treatments from children, including their own. Irrespective of culture of origin, all children should be appropriately protected from the dangerous expression of other people's beliefs until such time as they are old enough to make their own decisions. From reports it appears that this 13 year-old child was able to indicate that he wanted active treatment to save his life. It is very sad that his own mother refused to give consent to his potentially life-saving treatment and justified that refusal on the basis of her own religious beliefs and dogma."