It was the school that sounded the alarm. “Elias no longer sees what is written on the board,” explains his mother Sandrine, sitting next to her 11-year-old son, who is bored under his blonde hair. This sudden loss of vision is similar to that experienced by her eldest, Anaëlle, 13, who suffers from Stargardt disease, a rare genetic eye disease that affects the central area of ​​the retina.

The family from Val-d’Oise (who wish to testify anonymously) are worried about the youngest, 10 years old. Does the same fate await him? “We live with an ax over our heads,” sighs Camille, the father, who is having trouble coming to terms with this. The disease cannot be cured. In the most severe cases, there is a loss of central vision, making reading and writing difficult.

This November 16, Sandrine, Camille and their three children crowd into the consulting room of geneticist Stanislas Lyonnet, 65, director of the Imagine Institute, on the campus of the Necker-Enfants Malades hospital (AP-HP) in the 15th arrondissement of Paris . The exercise is delicate for this pediatrician, accompanied by a genetic counselor and a psychologist.

In a few minutes he must access the privacy of a family and draw its family tree, looking for ancestors, if any, at the end of the most convoluted branches. In the case of this family, the pathology is due to the presence in the children of two variants of the ABCA4 gene, one transmitted from the father and the other from the mother. Additional tests would have to be carried out to verify this. “No blood test!”, Elias winced. His father insists. They will come back.

Looking for a diagnosis, treatment

Each year, nearly thirty thousand families pass through the glass doors of the Imagine Institute in search of a diagnosis, treatment, or just a bit of hope. It is the first European center for research, care and teaching on genetic diseases – whose founding members include the French Association against Myopathies (AFM), which is organizing its telethon on December 8th and 9th (alongside AP-HP, Inserm). , the Paris Cité University, the Hospital Foundation and the City of Paris), the temple of French genetics.

His doctors are consulted like oracles by patients who come from far away, sometimes abroad. Half make a diagnosis, but only 15% receive appropriate treatment. For others, hiking can last a lifetime. A “Odyssey” (Odyssey diagnosis), say the Anglo-Saxons delicately.

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