Plans to genetically screen newborns for rare diseases are problematic

Rare diseases are often difficult to spot. They can escape detection until damage or an irreversible organ handicap has already settled. Last month, in the hope of preventing just this type of damage, the United Kingdom’s health secretary, Wes Wes Stting, announced a 10-year plan to carry out genetic tests for hundreds of rare conditions in part of the standard screening of the newborn in England. The world is likely to follow, with many feasibility programs already underway, especially in the United States and Australia. The street plan is to “jump” from the disease before it becomes symptomatic. But how much is it scientifically healthy, exactly?

The genome is a list of letters that seem to be read like a book, but it is a book in a language so new that only a small number of words have been deciphered. And, like any language, even these deciphered words could have several meanings. What we know of the risks associated with certain variants of genes is taken from decades of study of families at high risk of certain conditions. But we have little experience in the population -based genetic tests in low -risk individuals. There is no doubt that the type of planned screening will help certain children and families, but this could also lead to unnecessary tests and treatment for many others.

There is much more to develop most conditions than one genetic factor. A variant in the HNF4A Gene illustrates the problem. People with solid family history of a rare form of diabetes who bear this variant present a risk of 75% to develop the condition. However, the risk of diabetes in a person with this same variant who has no family history of the disease is only 10%. We cannot assume that a gene variant will behave in the same way in each population. Maybe these families with the HNF4A Variant and high levels of diabetes lack a protective gene that has not yet been discovered. There may be something in their common environment which, combined with their genetic risk, leads to diabetes.

The program provided for the newborn assumes that the variants of genes related to the disease lead to a high risk similar in everyone, but it is unlikely that this is correct. The work of researching variants of disease in healthy populations has just started. Until it is complete, we cannot know how many people have pathological variants that do not lead to conditions because they are protected by other factors. Do we really want the newborns to be the population on which we test our genetic hypotheses?

That is to say nothing of the ethical problems that will result from this program. How to obtain the informed consent of newborns when they simultaneously test hundreds of conditions? In the not too distant future, we could have a genetic database of each living person. How will it be protected and used in the future?

Of course, the newborn screening is nothing new. The difference here is the wide range of conditions to examine, the challenge of interpreting the results and sensitivity of the information collected. I worry that parents will feel obliged to accept this test, but will not be adequately informed of all the unknowns. I fear that the first vital stages of life were disturbed by hospital visits which could prove to be unnecessary. I fear that parents and pediatricians will increase by the decision to submit a child currently healthy to potentially invasive tests and treatments.

What is reasonable is to collect more information on the prevalence and behavior of the variants of the disease in the general population before genetic tests become a speculative screening tool in children. Although some will benefit from it, these success stories can be tiny compared to all potential damage.

Suzanne O’Sullivan is a neurologist and author of the age of diagnosis: illness, health and why medicine went too far