Register-based prevalence rates of childhood autism (CA), Asperger’s syndrome (AS) and other autism spectrum disorders (ASD) were calculated among children aged 7 years old of the 1997–2003 birth cohorts, living in four counties in France. The proportion of children presenting comorbidities was reported. 1123 children with ASD were recorded (M/F ratio: 4.1), representing an overall prevalence rate of 36.5/10,000 children (95 % CI 34.4–38.7): 8.8/10,000 for CA (95 % CI 7.8–9.9), 1.7/10,000 for AS (95 % CI 1.3–2.3) and 25.9/10,000 for other ASD (95 % CI 24.2–27.8). ASD prevalence significantly increased (p < 0.0001) during the period under study. The proportion of children with an intellectual disability was 47.3 %, all other comorbidities were present in less than 5 % of the cases.

Low but Increasing Prevalence of Autism Spectrum Disorders in a French Area from Register-Based Data.

Background 
The need for early treatment of autism spectrum disorders (ASD) necessitates early screening. Very few tools have been prospectively tested with infants of less than 12 months of age. The PREAUT grid is based on dyadic assessment through interaction and shared emotion and showed good metrics for predicting ASD in very-high-risk infants with West syndrome.


Methods 
We assessed the ability of the PREAUT grid to predict ASD in low-risk individuals by prospectively following and screening 12,179 infants with the PREAUT grid at four (PREAUT-4) and nine (PREAUT-9) months of age. A sample of 4,835 toddlers completed the Checklist for Autism in Toddlers (CHAT) at 24 months (CHAT-24) of age. Children who were positive at one screening (N = 100) were proposed a clinical assessment (including the Children Autism Rating Scale, a Developmental Quotient, and an ICD-10-based clinical diagnosis if appropriate) in the third year of life. A randomly selected sample of 1,100 individuals who were negative at all screenings was followed by the PMI team from three to five years of age to identify prospective false negative cases. The clinical outcome was available for 45% (N = 45) of positive children and 52.6% (N = 579) of negative children.


Results 
Of the 100 children who screened positive, 45 received a diagnosis at follow-up. Among those receiving a diagnosis, 22 were healthy, 10 were diagnosed with ASD, seven with intellectual disability (ID), and six had another developmental disorder. Thus, 50% of infants positive at one screening subsequently received a neurodevelopmental diagnosis. The PREAUT grid scores were significantly associated with medium and high ASD risk status on the CHAT at 24 months (odds ratio of 12.1 (95%CI: 3.0–36.8), p < 0.001, at four months and 38.1 (95%CI: 3.65–220.3), p < 0.001, at nine months). Sensitivity (Se), specificity, negative predictive values, and positive predictive values (PPVs) for PREAUT at four or nine months, and CHAT at 24 months, were similar [PREAUT-4: Se = 16.0 to 20.6%, PPV = 25.4 to 26.3%; PREAUT-9: Se = 30.5 to 41.2%, PPV = 20.2 to 36.4%; and CHAT-24: Se = 33.9 to 41.5%, PPV = 27.3 to 25.9%]. The repeated use of the screening instruments increased the Se but not PPV estimates [PREAUT and CHAT combined: Se = 67.9 to 77.7%, PPV = 19.0 to 28.0%].


Conclusions 
The PREAUT grid can contribute to very early detection of ASD and its combination with the CHAT may improve the early diagnosis of ASD and other neurodevelopmental disorders.

/pdf/infant-and-dyadic-assessment-in-early-community-based-hn05qzm1wc.pdf

Infant and dyadic assessment in early community-based screening for autism spectrum disorder with the PREAUT grid.

Resume L’autisme est un syndrome clinique dont la description si caracteristique a participe a la fondation de la psychiatrie de l’enfant. Pourtant, il reste le syndrome de tous les mysteres et de toutes les controverses. L’une d’elles concerne l’âge auquel le diagnostic d’autisme peut-etre porte precocement. Nous en discuterons les implications selon plusieurs axes : les donnees de l’epidemiologie en population generale et en population a risque ; le point de vue des parents quant au reperage precoce et leur parcours de soins pour arriver en France a un diagnostic ; l’etude des interactions parent–enfant a partir de films familiaux. Nous montrerons qu’un retard de developpement et des troubles precoces de la communication et des comportements sociaux ne suffisent pas a circonscrire le risque d’autisme en termes de trajectoire precoce avant un an ; qu’un changement de paradigme semble fecond dans les recherches les plus recentes, a savoir tenir compte de la qualite de l’interaction en termes de synchronie et de reciprocite, et egalement d’engagement emotionnel. Enfin, nous soulignerons les importants progres conduits en France pour abaisser l’âge du rendu diagnostique ces 20 dernieres annees.

Signes précoces d’autisme : d’où vient-on ? Où va-t-on ?

Background: There are many societal and cultural differences between healthcare systems and the use of genetic testing in the U.S. and France. These differences may affect the diagnostic process for Autism Spectrum Disorder (ASD) in each country and influence parental opinions regarding the use of genetic screening tools for ASD. Methods: Using an internet-based tool, a survey of parents with at least one child with ASD was conducted. A total of 162 participants from the U.S. completed an English version of the survey and 469 participants from France completed a French version of the survey. Respondents were mainly females (90%) and biological parents (94.3% in the U.S.; 97.2% in France).Results: The mean age of ASD diagnosis reported was not significantly different between France (57.5±38.4 months) and the U.S. (56.5±52.7 months) (p=0.82) despite significant difference in the average age at which a difference in development was first suspected (29.7 months (± 28.4) vs. 21.4 months (± 18.1), respectively, p=7.10-4). Only 27.8% of U.S. participants indicated that their child diagnosed with ASD had undergone diagnostic genetic testing, whereas 61.7% of the French participants indicated this was the case (p=2.7.10-12). In both countries, the majority of respondents (69.3% and 80% from France and the U.S., respectively) indicated high interest in the use of a genetic screening test for autism. Conclusions: Parents from France and the U.S. report a persistent delay between the initial suspicion of a difference in development and the diagnosis of ASD. Significantly fewer U.S. participants underwent genetic testing although this result should be regarded as exploratory given the limitations. The significance of these between country differences will be discussed.

/pdf/are-there-cultural-differences-in-parental-interest-in-early-196irbahy6.pdf

Are There Cultural Differences in Parental Interest in Early Diagnosis and Genetic Risk Assessment for Autism Spectrum Disorder

Autism spectrum disorders include a heterogeneous collection of conditions characterized by the syndrome of autism, namely, marked impairments in social interaction and communication and a markedly restricted and peculiar range of interests and activities. Neuroscience research on autism spectrum disorders is hindered by various different definitions utilized by contributors over the past century. Currently, the criteria for autism spectrum disorders are in flux; new diagnostic requirements for autism spectrum disorders have just been promulgated. Autism spectrum disorders include autistic disorder, Asperger syndrome, Heller syndrome, Rett syndrome, fragile X syndrome, and pervasive developmental disorders. The Rett syndrome is associated with mutations in the X-linked methyl-CpG-binding protein 2 located at the Xq28 region. Fragile X syndrome is associated with abnormalities in the X chromosome. With the exception of the Rett syndrome and the fragile X syndrome, there are likely multiple etiologies for the other autism spectrum disorders. Thus, autism spectrum disorders likely include conditions with disparate biological causes. Human brain imaging includes a spectrum of tools to identify both the structure and the function of the human nervous system utilizing a variety of energy sources and detection modalities. Anomalies in the physiology of the frontal and temporal lobes characterize subgroups of people with autism spectrum disorders. Dysfunction of the frontal and temporal lobes likely provides a pathophysiological basis for the social and language deficits characteristic of the disorders. Dysfunction of the serotonergic and cholinergic systems has been identified in subgroups of people with autism spectrum disorders to support the hypotheses that these systems play a role in the pathophysiology of autism spectrum disorders. Conflicting and contradictory results from reports on human brain imaging of autism spectrum disorders likely stem from the differences in the diagnostic tools, imaging procedures, participant populations, and other characteristics of individual investigations. Additionally, the small sample sizes employed in many imaging studies lack the power to establish a statistical significance. Future research to investigate the brain imaging of humans with autism spectrum disorders can be facilitated by the utilization of accurate diagnostic criteria and rating instruments. Additionally, the identification of demographic, educational, psychiatric, psychological, and neurological characteristics may help to classify people with autism spectrum disorders according to useful clinical groups. Investigation of genetic markers for particular neurotransmitters likely altered in autism spectrum disorders may lead to the discovery of genetic mutations characteristic of subgroups. Careful research including the spectrum of investigative tools will likely result in the identification of biological markers to identify distinct groups such as the Rett syndrome and fragile X syndrome.

Human Brain Imaging of Autism Spectrum Disorders

Resume Contexte et objectif L’augmentation de prevalence des troubles envahissants du developpement est documentee dans la litterature internationale, mais les donnees restent parcellaires en France. L’objectif est d’analyser l’evolution recente des prevalences des TED a partir des donnees des deux registres de population en France. Methode Ces deux structures enregistrent tous les cas de troubles envahissants du developpement chez les enfants residant dans les departements concernes au cours de leur huitieme annee de vie, apres accord parental. Les donnees sont recueillies a partir des dossiers medicaux disponibles dans les differentes sources de donnees et les diagnostics sont codes selon la Classification internationale des maladies (CIM10). Les donnees presentees ici concernent les enfants nes entre 1995 et 2002. Les taux de prevalence ont ete calcules pour 10 000 enfants residant dans leur huitieme annee dans chaque departement. Resultats Le taux de prevalence global dans la huitieme annee de vie sur l’ensemble de la periode etait de 31,9 pour 10 000 enfants en Haute-Garonne et de 34,9 pour 10 000 en Isere, avec une tendance a l’augmentation entre 1995 et 2002 significative en Haute-Garonne. Le sex-ratio etait de 3,8 et 3,5 respectivement en Haute-Garonne et en Isere. Dans les deux departements, environ la moitie des enfants presentait une deficience intellectuelle associee. Conclusion Les donnees issues des deux registres francais sont tout a fait comparables et montrent des taux de prevalence des troubles envahissants du developpement qui se situent dans la fourchette basse de ceux publies dans la litterature internationale.

T. Maffre

Papers

Prévalence de l’autisme et autres troubles envahissants du développement : données des registres français de population. Générations 1995–2002