Written by Julian Savulescu

Hypothetical Case 1: Enzyme Replacement Therapy for Gaucher’s Disease

Consider a hypothetical version of a real life disease, Gaucher’s Disease. Gaucher’s disease is an inherited disorder caused by a genetic mutation. The mutation means an enzyme– glucocerebrosidase — is not produced. A a result, glucerebrosides (fats) build up, damaging cells. This can cause bone fractures, liver enlargement, and bleeding but most importantly, brain damage. Once this has occurred it is irreversible.

Enzyme Replacement Therapy (ERT) is now available and for the purposes of this hypothetical case, the treatment offered, if given from the moment of birth, will prevent all damage (in real life current enzyme replacement treatments do prevent most symptoms, but do not affect nervous system involvement).

In our hypothetical case, a child is born to parents known to carry the mutation for Gaucher’s Disease, and prenatal testing has already confirmed that the baby is affected. ERT must be started at birth in order to prevent brain and other damage. However, the parents are Christian Scientists and refuse medical treatment. They believe prayer can cure their child’s condition.

Doctors are concerned the missing enzyme needs to be replaced before the child’s brain is damaged. They take the case to court where judges agree that therapy is in the child’s best interests.

The situation is complicated because therapy will need to continue for the rest of the child’s life. The child’s parents are brought in for further discussions, counselling and education. It is not clear whether they will comply with the regular requirements for enzyme replacement therapy, which must be given intravenously every two weeks. Questions are raised about whether the child should be brought into care to ensure the treatment continues.

The parents’ lawyers point out that the treatment is very expensive: $200 000 USD per year. It is not cost-effective according to the formula employed in their country, and distributive justice should preclude its use. They argue their child should be left alone. It is not only their wish but it is also required by justice.

Hypothetical Case 2: Gene Editing

The second hypothetical case takes place several generations later. Gene editing has advanced and has been shown to be safe, with few, if any, off target mutations. The couple are undergoing IVF because they know they are also carriers of Gaucher’s Disease and they hope to be able to select an unaffected embryo. Yet after multiple IVF attempts, they produce only one embryo and prenatal diagnosis confirms the embryo is affected by Gaucher’s Disease. Nonetheless they wish the embryo to be implanted. It is very unlikely they will produce another embryo and they don’t want to adopt. Their reasoning is the same as the parents in hypothetical 1: “It is God’s will. We are Christian Scientists. We will pray for God to cure the disease.”

Doctors are willing to transfer the affected embryo but point out that now gene editing could cure the disease. They could correct the genetic mutation so that the body naturally produces the normal amounts of the enzyme, glucocerebrosidase. This would be a one hit “silver bullet” that would cure the disease for the rest of the child’s life. It would correct the root cause: a genetic mistake. There would be no fortnightly injections. And it would be very cost-effective. Instead of costing $200 000 per year, every year, it would be a single cost of a few thousand dollars.

The parents continue to refuse on religious grounds. They believe prayer will cure their child.

Courts have previously authorised blood transfusions for children when parents have refused because they are Jehovah’s Witnesses. Courts might authorise enzyme replacement therapy if it were to prevent serious brain or other irreversible damage.

If it is in the child’s best interests to enforce enzyme replacement therapy, does the same reasoning apply to gene editing to correct such genetic disorders?

Nuffield Council Report on Gene Editing

The Nuffield Council on Bioethics has just produced an illuminating, thoughtful and provocative report on gene editing. In a nutshell, they argue that is an important potential tool in the fight against disease, and even to promote human well-being more generally (enhancement). However, the science must mature and they argue at this point for further research, but only after adequate public consultation and then law reform.

They are surely right. But the issue perhaps even more morally weighty than they credit. What is at issue is the fundamental correction of genetic mutation, the root cause of genetic disorders, and also a contributor to many common diseases.

You might think that it is within the zone of parental discretion to refuse enzyme replacement therapy in Gaucher’s disease. And so you might think it is in the zone of parental discretion to refuse gene editing for major genetic disorders. The Nuffield Council certainly doesn’t consider whether gene editing could ever be compulsory. But the very complexity and gravity of such a decision in these hypothetical cases illustrate what is at stake.

At the very least, children should have the chance to grow up unhindered by curable major diseases. For this reason, although we will face challenging ethical decisions like these,genome editing research is compulsory.