It's not a miracle cure, but there is real hope for all people with trisomy 21. A therapy, tested on a small number of patients, has improved some of their cognitive functions.
These results, considered “promising”, still need to be confirmed.
"The experience is very satisfactory, even if we remain cautious," summarized Nelly Pitteloud, head of the endocrinology department at the Vaud University Hospital Center (CHUV), presenting the study published Thursday in
Science
to the press .
A hormone to boost cognitive functions
Its hospital located in Lausanne, Switzerland, collaborated with a team from Inserm (within the Lille neuroscience and cognition laboratory) to test the effectiveness of a therapy based on the injection of the GnRH hormone into patients. carriers of trisomy 21, one of the most common chromosomal abnormalities.
Recent discoveries have indeed suggested that neurons expressing the hormone GnRH (Gonadotropin-Releasing Hormone), known to regulate reproduction via the hypothalamus, would also have an action on cognitive functions (memory, language, reasoning, learning, resolution problems…).
"We wondered if this hormone could play a role in the establishment of the symptoms present in carriers of trisomy 21", explained Vincent Prévot, director of research at Inserm.
In mice, the laboratory established that five strands of microRNA regulating the production of this hormone and present on chromosome 21 were deregulated.
The scientists succeeded in demonstrating that the progressive cognitive and olfactory deficiencies of these mice were closely linked to dysfunctional GnRH secretion.
They then proved that the reactivation of a normal GnRH system made it possible to restore cognitive and olfactory functions in mice with Down syndrome.
(1/3)
The injection of a #hormone known to regulate reproduction could be the basis of a new #therapy improving the cognitive functions of people with #trisomy21... pic.twitter.com/EvY4i2zJ6I
— Inserm (@Inserm) September 1, 2022
Access to this content has been blocked to respect your choice of consent
By clicking on "
I ACCEPT
", you accept the deposit of cookies by external services and will thus have access to the content of our partners
I ACCEPT
And to better remunerate 20 Minutes, do not hesitate to accept all cookies, even for one day only, via our "I accept for today" button in the banner below.
More information on the Cookie Management Policy page.
An improvement of between 10 and 30% in cognitive functions
Enthused by these results, Nelly Pitteloud's team took over.
A pilot clinical trial was conducted on seven men with Down syndrome, aged 20 to 50, between October 2020 and May 2022. Patients received a dose of GnRH every two hours subcutaneously for 6 months, via a pump on the arm.
Cognition and smell tests as well as MRI examinations were carried out before and after the treatment.
"There was an improvement of between 10% and 30% in cognitive functions, in particular visuo-spatial function, three-dimensional representation, understanding of instructions and attention," said Nelly Pitteloud.
Thus, a patient who struggled to reproduce the diagram of a 3D cube before the start of treatment, managed to draw a bed correctly at the end.
Clinically, cognitive performance increased in 6 out of 7 patients, improvements confirmed by brain imaging.
However, unlike what happened with the mouse, the treatment had no impact on olfaction.
“still a lot of work to do”
These “promising” results need to be confirmed.
“Clinical work focused on just seven male patients;
to prove the effectiveness of GnRH treatment in trisomy 21, we still have a lot of work to do,” acknowledged Nelly Pitteloud.
The authors of the study recognize other biases, such as the presence of patients who are already very stimulated by their parents.
They would now like to include people with more varied profiles, including some with degenerative signs such as Alzheimer's.
In the fall, a larger study involving 50 to 60 people and a placebo should be launched.
The researchers hope to include "a third" of women, who will not have to be on contraception or wish to become pregnant, the hormone GnRH regulating reproduction.
“Allow them to be a little more independent”
"We are not going to cure the cognitive disorders of people with Down's syndrome, but in our results, the improvement already seems quite essential to hope to increase their quality of life", rejoiced Nelly Pitteloud.
The results of the study are also welcomed by independent experts.
Describing it as a "tour de force", Fabian Fernandez, a specialist in cognition and trisomy 21 at the University of Arizona (United States), judged its results "irreproachable".
“It is difficult to imagine how this treatment strategy could be deployed in children and adolescents still in puberty or in women of childbearing age,” he told AFP, however.
And “it is difficult to predict what these improvements portend for the daily lives of patients.
For some, it might allow them to be a little more independent,” he said.
Health
Marthe Gautier, co-discoverer of trisomy 21, has died
Nantes
Nantes: In this giant shared apartment, young workers and young people with disabilities form "a shock team"
Trisomy
Health
study
Brain