Speaker: Jaqueline London, Emeritus Professor, Université de Paris, France.
The webinar’s recording is from 21 April 2021.

Down syndrome (DS, also called trisomy 21) is characterised by many developmental abnormalities, including intellectual disability, which could be related at least to sleep disturbances. Sleep disturbances in early childhood of persons with DS have been mostly underestimated, especially on their consequences on physical and neural development and functioning.

When a person sleeps, it is mostly the sleep quality that is important and can be defined by the number and the length of the various stages of the sleep (called SWS: slow wavelength sleep or NREM) and by the number of REM (Rapid Eye Movement). Sleep affects learning and development in humans and in other animals, and during sleep, many very important neuronal pathways regarding growth hormone and melatonin synthesis, which is related to acetylcholine synthesis and uptake, metabolisms of dopamine, glutamate, serotonin, calcium, adenosine, and glucose. All these molecules contribute to the required synergy for an active and productive day. Thus bad sleep may contribute to the behavioural and cognitive deficits of patients with mental retardation especially in the early childhood.

Although sleep disturbances in patients with DS have already been reported in the early 70th, not enough attention has been used to improve the sleep quality of DS persons. More recently, the attention of sleep disturbances in the general population, especially for OSA (Obstructive Sleep Apnea) has been pointed and devices for this condition are now well used and also at a moderate rate for persons with DS. Sleep apnea is characterised by increased arousals, mainly because when the throat deepens during sleep, the airway muscles in the throat also deepen, thus preventing the patient from breathing normally. Many recent international reports have shown that 60% of the children with DS syndrome aged even 4 months have OSA even if they do not snore and if their parents report not having any sleep problem.

These patients have not only sleep apnea but also sleep fragmentation (frequent sleep arousals without apnea) and sleep breathing disorders (SBD), which are important for normal development.
We will provide some new practical information to better handle these problems in the population with DS according to age. We will also specifically mention the relation between apnea and COVID-19 in these days of the pandemic.

Biography

Jacqueline London (Emeritus Professor at University Paris-Diderot) has completed her PhD in the Pasteur Institute under the direction of Pr. Jacques Monod and Professor M. Goldberg in the field of protein folding and bacteriology. She moved to immunology in Necker’s hospital under the direction of Pr JF Bach and then was a visiting scientist at NIH.

After coming back to Paris, she set up a laboratory in molecular biology at the Blood Center and cloned glycophorin A and B (13 papers). She then moved again to Necker’s Hospital, where she joined the group working on Down syndrome (Trisomy 21) and published some 35 papers on different aspects of trisomy 21 using transgenic mice for some chromosome 21 genes: APP, CBS, DYRK1,A and SOD1.

She published the first research papers on sleep in animal models for DS and gave several talks on sleep problems in DS, which were not recognised as a real phenotype in the early 2000s.

For many years, she tried to push the correlation between Alzheimer’s disease (AD) and Down syndrome (DS) and recently worked on neurotransmitters in some transgenic mice APP and DYRK1A. She has also been teaching Parkinson’s disease, Alzheimer’s disease, and protein aggregates for many years.

She settled in 1990 AFRT (French Association for Research on Trisomy 21) and is now AFRT Vice-president and initiated in the 2005 the international day for Trisomy 21 which is now recognised as World Down Syndrome Day (WDSD).