Cranio-Facial Characteristics in Children with Autism Spectrum Disorders (ASD)

Abstract

Background: Cranio-facial anomalies frequently occur in neurodevelopmental disorders because both face and brain are derived from neuroectoderm. The identification of differences in the facial phenotype of children with Autism Spectrum Disorders (ASD) may reflect alterations in embryologic brain development in children with ASD. Methods: we evaluated 33 caucasian children with ASD using a 2D computerized photogrammetry. Anthropometric euclidean measurements and landmarks located on the soft tissue of the face and head, were based on five cranio-facial indexes. Relationships between anthropometric z-scores and participant characteristics (i.e., age, Global IQ, severity of autistic symptoms measured using the CARS checklist) were assessed. Results: Cephalic index z-score differed significantly from 0 in our ASD group (p = 0.019). Moreover, a significant negative correlation was found between Facial Index z-score and CARS score (p = 0.003); conversely, a positive correlation was found between Interchantal Index z-score and CARS score (p = 0.028). Conclusion: our measurements shows a dolichocephalic head shape which is not correlated with autism severity. Importantly, two craniofacial markers were significantly correlated with autism severity: increased orbital hyperthelorism and decrease of height of the facial midline. These data support previous findings of craniofacial anomalies in autism spectrum disorder suggesting an “ASD facial phenotype” that could be used to improve ASD diagnoses.

A Preliminary Study on Cranio-Facial Characteristics Associated with Minor Neurological Dysfunctions (MNDs) in Children with Autism Spectrum Disorders (ASD)

“…The correlations between anthropometric z-scores, demographic characteristics, global QI, CARS and MND are shown in Table 3. Most of these correlations were previously described in our study [11]. Moreover, significant, large positive correlations were found between cephalic index and sensory deficits (r = 0.547, p-value < 0.001) and between cephalic index and c-MND (r = 0.469, p-value = 0.005).…”

“…Our recent research [11] identified a dolichocephalic head shape in ASD children, which did not correlate with autism severity. This finding was compatible with previous research, showing that brain and head size is a relatively non specific finding in autism [27] and suggesting an abnormal brain growth trajectory during the in-utero period, after the 22nd week of amenorrhea, in children with ASD who showed postnatal head overgrowth [31].…”

“…Recent studies [9][10][11] showed that children diagnosed with ASD have a distinctive facial phenotype, which correlates with symptom severity, suggesting a biological and anatomical subset of ASD.…”

“…For a detailed description of the morphological assessment protocol see Tripi et al [11] Cranio-facial examination of the ASD group employed a mixed approach of computerized photogrammetry and classic anthroposcopy. The examination was conducted by the same author (GT) in the same testing rooms.…”

“…Previous studies [9][10][11] have shown that facial morphology differed significantly in individuals with ASD diagnoses; identifying subsets of ASD boys, with distinctive craniofacial morphology, associated with greater severity of ASD symptoms. This could suggest an "ASD facial phenotype", representing a new physical biomarker which could be used to improve ASD diagnosis.…”