Description

Researchers will contact interested parents to assess eligibility and provide detailed study information. Parents will provide written consent before completing baseline assessments (T0) and based on the scores at the main outcome measures, children will be assigned to the correct group. Infants with no signs of concern and siblings of TD children will be allocated to Group 1 (CM); infants with no signs of concern (scores at the Griffiths-3 and CSBS-ITC in the normal range) and siblings of ASD children will be allocated to Group 2 (AM); infants with General Quotient score below 85 using Griffiths-3 and/or at least one score above the "concern" cutoff using the CSBS-ITC will be allocated to Group 3 (EI). Families allocated to Groups 2 and 3 will start the intervention within one month from the baseline assessment. Families allocated to Group 1 will perform only the evaluations at different time points. Assessments will be conducted at baseline (T0), which will be when the parents give their consent and within the 8 months of life of the child, after 6 months from the start of the intervention (T1) and after 12 months from the start of the intervention (T2).

Technological assessment of social behaviour and joint attention:

• video recording of ESCP through Kinect Azure camera to collect and analyse quantitative data related to joint attention.

The administration of the ECSP-I will be video-recorded through an Azure Kinect camera to extract automatically gaze orientation and quantitatively assess Joint Attention.

• Eye-tracker acquisitions An experimental Eye-Tracker Screening (ETS) protocol for children will also be developed. Specifically, short videos will be used to measure the children's ability to process familiar/unfamiliar faces and to respond to social stimuli, particularly referential gaze. The children's eye movements will be analysed using the eye-tracker (Tobii Pro Fusion) and extracted using the appropriate software.

At recruitment (T0), anamnestic, sociodemographic data and auxological and clinical parameters at birth will be collected.

Biomolecular assessment Saliva samples will be collected using 3 different kits, respectively for DNA or RNA extraction, and for protein detection, through spongy swabs that are inserted into the baby's mouth, leading the saliva collection non-invasive, simple, fast, and most importantly, painless. Saliva samples will be collected from all the probands (at T0, T1 and T2) and from their siblings and parents at T0 to assess parent-to-child genetic transmission in relation to the risk of ASD. If possible, a sample of approximately 40 mL of blood (from the parents) will be collected.

Biological samples from family quartet will be collected as follow:

1. In all the enrolled children, their older siblings and parents, genetic analysis will be conducted by a Next-Generation Sequencing (NGS) gene-targeted panel approach to analyse genes involved in synaptogenesis and immunogenetic regulation.
2. Epigenetic analysis of the miRNome in saliva collected from all enrolled children at all time-points will be performed by NGS. Epigenetic analysis will allow to define a panel of microRNAs that can differentiate between ASD children and children with typical development.
3. Analysis of inflammatory cytokines and neurotrophic factors using an automated immunoassay system (ELLA, Biotech) will be performed in probands at T0, T1 and T2. Parents will also be characterized for cytokine and lymphocyte subset at T0.

Correlations between clinical parameters and all biological variables (genetic, epigenetic, inflammatory) will be performed to correlate molecular biomarkers with neurodevelopmental changes in follow-up and pre-post intervention.

Sample size

Since the importance of ECSP-I in this project, as behavioural outcome measures as a tool for reaching quantitative data through technology, we calculate the sample size to detect an association between the ECSP-I score and the groups (1, 2 and 3) at each time point. The calculation was performed based on preliminary data (not already published) from the Italian Version of ESCP (ECSP-I). Assuming a standard deviation of 0.56 for the ECSP-I scale and a significance level α= 0. 01, obtained by applying the Bonferroni correction for multiple comparisons, performed in pairs between groups, to the type I error, we obtained a sample size of 14 subjects per group to detect a difference of 0.8 between the means of each group using a 2-tailed Student's t-test for independent samples, with a power of 80%. Assuming a drop-out rate of 10%, the required sample size increases to 16 subjects per group, that is 48 subjects in total.

Statistical analysis

Analysis (using STATA or SPSS 28.00) will follow standard methods for trials using comparisons between the three groups. First, a study of the maturation trajectories of the infants will be carried out, with a description of the pre-post intervention changes in the tests carried out. Secondly, quantitative evaluations of joint attention data and molecular markers will be performed, detected, and described through mean and standard deviation in case of Gaussian distribution of variables, or median and interquartile range in case of non-Gaussian distribution. The normality of distributions will be assessed by applying the Shapiro-Wilk test. For categorical variables, absolute frequencies and percentages will be reported. Genetic analysis of intra-familial allelic inheritance will be conducted by AFBAC (Affected Family-Based Controls) and TDT (Transmission Disequilibrium Test) . The immunological parameters obtained from the groups of ASD children and children with typical development will be analysed using a nonparametric Mann-Whitney test that will allow to identification of specific immunological biomarkers of ASD-associated neuroinflammation. Moreover, clinical parameters will be correlated with immunological biomarkers characteristic of ASD children. Finally, epigenetic analysis will allow us to define a panel of microRNAs that can differentiate between ASD children and children with typical development. Using computer algorithms, the potential targets, pathways, and biological functions deregulated by this group of miRNAs will be analysed. These data will also be analysed concerning the clinical parameters evaluated in the study and both the genetic and inflammatory characterization of the subjects studied.