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Guthrie test: screening for healing
Not compulsory … but strongly recommended
Within 3 days after the baby is born, before leaving the maternity ward, the pediatrician will ask your permission to perform the Guthrie test. This test is not compulsory, you can obviously refuse it, but according to Professor Michel Roussey, pediatrician at Rennes University Hospital and president of AFDPHE *, that would not be very wise. Why ? Because it makes it possible to detect serious diseases which, if they are not taken care of from birth, are incurable and cause significant mental and / or physical delays. In 2011, there was 100% screening of newborns (only 100 parents out of 840 refused). The financial aspect should not block you: the test is fully reimbursed by health insurance, you will not have to pay anything!
The diseases detected
There are now 5 diseases detected. Parents do not necessarily know they are carriers of the gene for one of these serious and rare diseases. They are therefore undetectable at birth if a blood test is not done. Diagnosing them allows the baby to be treated immediately. He thus escapes disability and can have a completely normal life.
— Phenylketonuria : the 1st detected by the test. It affects one in 15000 births. It is the absence of an enzyme that prevents the transformation of the phenylalanine contained in almost all foods. It causes mental retardation in a few months if it is not taken care of. Detected at birth, it can be countered by putting the child on a diet low in phenylalanine as soon as possible.
— Congenital hypothyroidism : concerning 1 in 4000 children, it causes mental retardation linked to insufficient thyroid hormones. Once diagnosed, it is enough to compensate for this lack of hormones by the daily oral intake of thyroid hormones.
– The 3rd disease added is congenital adrenal hyperplasia. Affecting 1 in 18000 births, it can in particular be responsible for a rapid death from dehydration from the 2nd week of the child’s life. It is supported by putting the child on adrenal hormones.
— Sickle cell anemia : alteration of hemoglobin which has the role of transporting oxygen in the blood. It then exposes the child to all kinds of infections which lead to serious complications.
– and since 2002, Cystic fibrosis is added to the test: although this pulmonary insufficiency does not have a treatment that can cure it completely, it is still detected because once diagnosed, immediate treatment improves life expectancy and quality of life of the child.
Why limit the test to screening for these 5 pathologies? Criteria have been developed so as not to get lost in unnecessary screening for diseases that medicine cannot cure. Conditions :
– illness is a major health problem
– medicine has a treatment to treat the disease.
– the protocol for this treatment is well defined.
– the patient is recognized at a pre-symptomatic stage, when the disease has not yet declared itself.
– the natural history of the disease, that is to say its evolution, is understood.
If a new pathology is to be added to the test, it must absolutely meet these conditions., so as not to pose ethical problems. The only exception to the rule is cystic fibrosis: its screening has been the subject of long discussions. It cannot be cured, but it is still part of the test. The fact of being able to greatly improve the quality of life of the child, once the pathology was diagnosed, made it possible to include him in the Guthrie test.
The course of the Guthrie test
Before leaving the maternity ward, when the newborn is 3 days old, a small incision is made in his heel and 5 drops of blood are taken. By taking a small bottle of sugar water at the same time, the baby does not feel any discomfort. This way of proceeding avoids having to take a blood test. Indeed, only a few drops are enough. They are then placed in specific places on blotting paper. Once dried, this paper filled in with the child’s name is sent to the regional association responsible for screening and sent to the analysis laboratory. The adage “no news, good news” is true here because if you have no feedback, baby has no disease!
Conversely, if the test is positive, a doctor will contact you for further examinations. A treatment adapted to your infant will be quickly put in place, allowing him to grow in the most normal way possible.
Towards an expanded Guthrie test …
What if this test made it possible to detect more than 50 pathologies? We hear a lot about an expanded Guthrie test. This is the case in several countries today, such as Austria, which is already detecting 29 different pathologies. A technological innovation allows this expansion: tandem mass spectrometry. A single drop of blood is now enough to detect 50 new rare pathologies. In France, the Haute Autorité de Santé (HAS) has accepted the principle. Laboratories must now obtain the devices capable of carrying out these analyzes. However, Professor Michel Roussey believes that it is not in Guthrie’s philosophy to screen for as many diseases as possible. “The screening must be used for something,” he insists. If there is no cure for a detected disease, what is the use of the test? “. Another more ethical question raised by the pediatrician: this test should be used by the child, not the family. If it is open to 50 pathologies, of which only a small number are “curable”, a question arises: will it be used only for the child or will the child be used to detect a family pathology? It is therefore necessary, according to the doctor, to ensure that this opening is well framed, so that the Guthrie test remains fully useful.
* AFDPHE: French Association for the Screening and Prevention of Childhood Handicaps
Guthrie test: a bit of history …
Developed on an experimental basis in 1961 by Dr Robert Guthrie, this test is the result of numerous experiments. This American doctor had personal reasons for continuing this research, since one of his children was mentally retarded, and one of his nieces disabled by phenylketonuria, for lack of being detected in time. He succeeded in developing a test to detect this pathology, the now famous Guthrie test, practiced in France since 1972, and used in many countries.