PhD Defense: Mme Tania Bitar


on the November 27, 2018

from 14h to 18h
School of Medicine
Amphi. D

Under the scientific supervision of Prof. Christian Andres and Prof. Walid Hleihel from USEK University, Liban.

Epidemiological, genetic and metabolomic study of autism spectrum disorders in Lebanon

Mrs. Tania Bitar will present her thesis work on the epidemiological, genetic and metabolomic study of autism spectrum disorders in Lebanon. This work was done under the scientific direction of Prof. Christian Andres (Neurogenomic and Neuronal Physiopathology Team) and Prof. Walid Hleihel from USEK University of Lebanon.


The etiology of autism spectrum disorders (ASD) is complex and multifactorial involving a strong genetic component and environmental factors. Indeed, several studies have shown that pre or postnatal risk factors can increase the risk of ASD. In addition, many candidate genes have been identified either by copy number variation (CNV) and/or single nucleotide variation (SNV). However, to date, the pathophysiological mechanisms are still poorly known and there is no biomarker facilitating early diagnosis of ASD to improve patient management and outcomes. The causes of ASD are not yet fully understood and the majority of the studies on ASD have been conducted in Western populations. Thus, as part of our project, we wanted to study a group of Lebanese patients with ASD and our objectives focus around three aspects:

1. Identification of environmental risk factors in order to better understand the pathology and to try to reduce as much as possible the risks in the future. The results of this study showed that several factors such as consanguinity, stress during pregnancy and prematurity appear to be risk factors.

2. Identification of structural variations in the genome of children with ASD in order to evaluate the contribution of CNV by high resolution CGH array approach. This study allowed us to identify new candidate genes in ASD whose biological functions correspond to processes involved in neuronal development and synaptic functions. In addition, we were able to confirm abnormalities in regions and genes already mentioned in previous studies on ASD.

3. Identification of urinary metabolites and associated metabolic pathways to provide biomarkers for early diagnosis and for a better understanding of the pathophysiology of the disease. New metabolites have been identified, which could open perspectives in the identification of new pathophysiological pathways. In addition, we confirmed variations already mentioned in the literature concerning certain metabolites that could represent robust markers of the disease.

This study, although preliminary because of the relatively moderate number of included patients, allowed us to identify new genes and new metabolites that may open new hypotheses, and confirmed previous observations made in other Ethnic and geographic populations.


ASD, environment, CGHarray, CNV, metabolomics, urine, biomarkers.


Bitar T, Mavel S, Emond P, Nadal-Desbarats L, Lefèvre A, Mattar H, Soufia M, Blasco H, Vourc'h P, Hleihel W, Andres CR (2018) Identification of metabolic pathway disturbances using multimodal metabolomics in autistic disorders in a Middle Eastern population. J. Pharm. Biomed. Anal., 152:57-65.

#Tours #iBrain #UMR1253 #Autism #Liban #Metabolomics

Contact :
Prof. Christian Andres :